Professor
- Locations
- Lab 425
Room 414 - Phone numbers
- 7754 (Office)
64 3 479 7754 (Office Direct Dial)
4600 (Lab) - harald.schwefel@otago.ac.nz
- Research Group
- https://www.physics.otago.ac.nz/research/resonantoptics/
Biography
I began my physics training in Germany at the Brandenburg Technical University in Cottbus. In 1998 I began graduate study at Yale University, USA where I received my PhD in theoretical physics in 2004 on the topic of chaotic dielectric resonators. Following a short stay in Japan, I established myself as an experimental physicist and later group leader at the Max Planck Institute for the Science of Light in Germany. In September 2015 I joined the Department of Physics at the University of Otago and have reestablished my laboratory there.
My research is centered on the interaction of light and matter in dielectric materials and in particular in resonantly enhanced interactions. Currently I am active in the field of nonlinear optics where I am particularly interested in optical frequency conversion. To achieve the required high field strengths I work with ultra high quality optical resonators, which I fabricate out of crystalline materials. My current focus is on enabling the nonlinear interaction of widely spaced frequency bands that usually do not interact, such as the microwave and the visible domain of the electromagnetic radiation.
Publications
Shao, L., Nan, T., Zhang, Y., Schwefel, H. G. L., & He, J. (2026). Dynamically control in a stretchable terahertz metasurface fabricated via 3d aerosol jet printing. Journal of Physics D, 59, 015103. doi: 10.1088/1361-6463/ae23db Journal - Research Article
Schwefel, H. (2025, May). Resonating with light. University of Otago, Dunedin, New Zealand. [Inaugural Professorial Lecture]. Other Research Output
Christensen, J. T., Trainor, L. S., Azeem, F., Sedlmeir, F., Strekalov, D. V., & Schwefel, H. G. L. (2025). Newton's rings for absolute distance measurement. Optics Letters, 50(23), 7215-7218. doi: 10.1364/OL.572001 Journal - Research Article
Petersen, A. R., Paulsen, P., Sedlmeir, F., Lambert, N. J., Schwefel, H. G. L., & Suresh, M. I. (2025). Visualization and selective manipulation of sub-terahertz whispering gallery modes. Applied Physics Letters, 127(21), 211102. doi: 10.1063/5.0293907 Journal - Research Article
Tian, C., Punzalan, J., Becker, P., Bohatý, L., Gordon, K. C., Blaikie, R., Schwefel, H. G. L., & Sedlmeir, F. (2025). Cascaded Raman lasing in a lithium tetraborate whispering gallery mode resonator. Photonics Research, 13(8), 2232-2239. doi: 10.1364/PRJ.560671 Journal - Research Article
2026
Journal - Research Article
Shao, L., Nan, T., Zhang, Y., Schwefel, H. G. L., & He, J. (2026). Dynamically control in a stretchable terahertz metasurface fabricated via 3d aerosol jet printing. Journal of Physics D, 59, 015103. doi: 10.1088/1361-6463/ae23db
2025
Journal - Research Article
Christensen, J. T., Trainor, L. S., Azeem, F., Sedlmeir, F., Strekalov, D. V., & Schwefel, H. G. L. (2025). Newton's rings for absolute distance measurement. Optics Letters, 50(23), 7215-7218. doi: 10.1364/OL.572001
Petersen, A. R., Paulsen, P., Sedlmeir, F., Lambert, N. J., Schwefel, H. G. L., & Suresh, M. I. (2025). Visualization and selective manipulation of sub-terahertz whispering gallery modes. Applied Physics Letters, 127(21), 211102. doi: 10.1063/5.0293907
Tian, C., Punzalan, J., Becker, P., Bohatý, L., Gordon, K. C., Blaikie, R., Schwefel, H. G. L., & Sedlmeir, F. (2025). Cascaded Raman lasing in a lithium tetraborate whispering gallery mode resonator. Photonics Research, 13(8), 2232-2239. doi: 10.1364/PRJ.560671
Tian, C., Becker, P., Bohatý, L., Blaikie, R., Schwefel, H. G. L., & Sedlmeir, F. (2025). Broadband second-harmonic generation in an x-cut lithium tetraborate whispering gallery mode resonator. Optics Letters, 50(17), 5246-5249. doi: 10.1364/OL.567843
Lambert, N. J., Longdell, J. J., Schwefel, H. G. L., Schumer, A., & Rotter, S. (2025). Coherent control of magnon–polaritons using an exceptional point. Nature Physics. Advance online publication. doi: 10.1038/s41567-025-02998-3
Suresh, M. I., Sedlmeir, F., Vogt, D. W., Santamaría Botello, G., Strekalov, D. V., & Schwefel, H. G. L. (2025). Multichannel upconversion of terahertz radiation in an optical disk resonator. Optics Express, 33(5), 10302-10311. doi: 10.1364/OE.557651
Conference Contribution - Published proceedings: Abstract
Suresh, M., Sedlmeir, F., Vogt, D., & Schwefel, H. (2025). Resonant electro-optic upconversion for next-generation photonic radiometers. In V. S. Ilchenko, A. M. Armani, J. V. Sheldakova, A. V. Kudryashov & A. B. Matsko (Eds.), Proceedings of SPIE (Vol. PC13349): Laser Resonators, Microresonators and Beam Control XXVII. PC133490H. SPIE. doi: 10.1117/12.3047467
Other Research Output
Schwefel, H. (2025, May). Resonating with light. University of Otago, Dunedin, New Zealand. [Inaugural Professorial Lecture].
2024
Journal - Research Other
Urban, L., Santure, A. W., Uddstrom, L., Digby, A., Vercoe, D., Eason, D., … Kākāpō Recovery Team, including Thompson, T., Weinzweig, N., Whittaker, M., and also Wylie, M. J., … Le Lec, M. F., Guhlin, J., … Alexander, A., Fuentes-Cross, P., Dearden, P. K., Gemmell, N. J., Azeem, F., Weyland, M., Schwefel, H. G. L., … Morales, H. E. (2024). The genetic basis of the kākāpō structural color polymorphism suggests balancing selection by an extinct apex predator. PLoS Biology, 22(9), e3002755. doi: 10.1371/journal.pbio.3002755
Conference Contribution - Published proceedings: Abstract
Suresh, M. I., Sedlmeir, F., Vogt, D. W., & Schwefel, H. G. L. (2024). Upconversion of multiple non-resonant THz channels in an optical microresonator. Proceedings of the Te Whai Ao Dodd-Walls Centre (DWC) Symposium. Retrieved from https://www.doddwalls.ac.nz/
Paulsen, P. C., Suresh, M. I., Lambert, N. J., Schwefel, H. G. L., & Sedlmeir, F. (2024). Monolithic optical and microwave resonator-based frequency comb generation. Proceedings of the Te Whai Ao Dodd-Walls Centre (DWC) Symposium. Retrieved from https://www.doddwalls.ac.nz/
Ng, V., Trainor, L. S., Schwefel, H. G. L., Coen, S., Erkintalo, M., & Murdoch, S. G. (2024). Photonic belt resonators for broadband frequency combs. Proceedings of the Te Whai Ao Dodd-Walls Centre (DWC) Symposium. Retrieved from https://www.doddwalls.ac.nz/
Petersen, A., Suresh, M. I., Sedlmeir, F., & Schwefel, H. G. L. (2024). Perturbation of whispering gallery modes using high-index substrates. Proceedings of the Te Whai Ao Dodd-Walls Centre (DWC) Symposium. Retrieved from https://www.doddwalls.ac.nz/
Christensen, J. T., Azeem, F., Trainor, L. S., Strekalov, D. V., & Schwefel, H. G. L. (2024). Newton's Rings interferometry for distance calibration in whispering-gallery mode resonators. Proceedings of the Te Whai Ao Dodd-Walls Centre (DWC) Symposium. Retrieved from https://www.doddwalls.ac.nz/
Azeem, F., Christensen, J. T., Sedlmeir, F., & Schwefel, H. G. L. (2024). Exploring laser self-injection locking enabled by crystalline whispering gallery mode resonators. Proceedings of the Te Whai Ao Dodd-Walls Centre (DWC) Symposium. Retrieved from https://www.doddwalls.ac.nz/
Tian, C., Sedlmeir, F., Becker, P., Bohatȳ, L., Blaikie, R., & Schwefel, H. G. L. (2024). SHG in x-cut lithium tetraborate (LB4) whispering gallery mode resonators. Proceedings of the Te Whai Ao Dodd-Walls Centre (DWC) Symposium. Retrieved from https://www.doddwalls.ac.nz/
Lambert, N. J., Sedlmeir, F., Paulsen, P. C., Suresh, M. I., & Schwefel, H. G. L. (2024). Optimising electro-optic resonators for efficient transduction. Proceedings of the Te Whai Ao Dodd-Walls Centre (DWC) Symposium. Retrieved from https://www.doddwalls.ac.nz/
Suresh, M. I., Sedlmeir, F., Vogt, D. W., & Schwefel, H. G. L. (2024). Multichannel upconversion of THz radiation in an optical microresonator. Proceedings of the 49th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz). IEEE. doi: 10.1109/IRMMW-THz60956.2024.10697900
2023
Journal - Research Article
Suresh, M. I., Schwefel, H. G. L., & Vogt, D. W. (2023). Gallium arsenide whispering gallery mode resonators for terahertz photonics. Optics Express, 31(20), 33056-33063. doi: 10.1364/OE.498406
Qureshi, P. C., Ng, V., Azeem, F., Trainor, L. S., Schwefel, H. G., Coen, S., … Murdoch, S. G. (2023). Kerr microresonator dual-comb source with adjustable line-spacing. Optics Express, 31(22), 36236-36244. doi: 10.1364/OE.501110
Ma, L., Trainor, L. S., King, G. G. G., Schwefel, H. G. L., & Longdell, J. J. (2023). Optically detected magnetic resonance to characterize atomlike microwave-optical transducers. Physical Review A, 107, 053514. doi: 10.1103/PhysRevA.107.053514
Lambert, N. J., Trainor, L. S., & Schwefel, H. G. L. (2023). Microresonator-based electro-optic dual frequency comb. Communications Physics, 6(1), 89. doi: 10.1038/s42005-023-01197-x
Ng, V., Azeem, F., Trainor, L. S., Schwefel, H. G. L., Coen, S., Erkintalo, M., & Murdoch, S. G. (2023). Wideband multimode optical parametric oscillation in a Kerr microresonator. Optics Express, 31(4), 5475-5482. doi: 10.1364/OE.480030
Conference Contribution - Published proceedings: Full paper
Azeem, F., Trainor, L. S., Gao, A., Isarov, M., Strekalov, D. V., & Schwefel, H. G. L. (2023). Whispering gallery mode resonators: An alternate platform for Ti:sapphire lasers and amplifiers. Proceedings of the International Conference on Emerging Trends in Electrical, Control, and Telecommunication Engineering (ETECTE). IEEE. doi: 10.1109/ETECTE55893.2022.10007203
Conference Contribution - Published proceedings: Abstract
Kessenich, H., Suresh, M. I., Platt, L., Vogt, D. W., Sedlmeir, F., Schwefel, H. G. L., & Seppala, A. (2023). Photonic radiometers for next-generation stratospheric ozone detection. Proceedings of the American Geophysical Union (AGU) Fall Meeting: Wide. Open. Science. A41I-2732. Retrieved from https://www.agu.org
Qureshi, P. C., Ng, V., Azeem, F., Trainor, L. S., Schwefel, H. G. L., Coen, S., … Murdoch, S. G. (2023). Tunable dual comb source in a Kerr microresonator. Proceedings of the Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC). doi: 10.1109/CLEO/Europe-EQEC57999.2023.10232518
Ng, V., Qureshi, P. C., Azeem, F., Trainor, L. S., Schwefel, H. G. L., Coen, S., … Murdoch, S. G. (2023). Magnesium fluoride photonic-belt resonators for generating broadband frequency combs. Proceedings of the Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC). doi: 10.1109/CLEO/Europe-EQEC57999.2023.10232164
Trainor, L. S., Ma, L., King, G. G. G., Schwefel, H. G. L., & Longdell, J. J. (2023). Microwave-optical double resonance in an erbium-doped whispering-gallery resonator\n. Proceedings of the Te Whai Ao Dodd-Walls Centre (DWC) Symposium. (pp. 44). Retrieved from https://www.otago.ac.nz/dodd-walls
Tian, C., Sedlmeir, F., Blaikie, R., & Schwefel, H. (2023). Nanocrystals on the crystalline whispering gallery mode resonator\n. Proceedings of the Te Whai Ao Dodd-Walls Centre (DWC) Symposium. (pp. 43). Retrieved from https://www.otago.ac.nz/dodd-walls
Ng, V., Qureshi, P. C., Azeem, F., Trainor, L. S., Schwefel, H. G. L., Coen, S., … Murdoch, S. G. (2023). Broadband frequency combs in photonic belt resonators\n. Proceedings of the Te Whai Ao Dodd-Walls Centre (DWC) Symposium. (pp. 31). Retrieved from https://www.otago.ac.nz/dodd-walls
Lambert, N. J., Sedlmeir, F., Yue, G., & Schwefel, H. G. L. (2023). Hot spot driving of a large whispering gallery mode resonator. Proceedings of the Te Whai Ao Dodd-Walls Centre (DWC) Symposium. (pp. 19). Retrieved from https://www.otago.ac.nz/dodd-walls
Suresh, M., Vogt, D., Platt, L., Kessenich, H., Seppälä, A., & Schwefel, H. (2023). GaAs resonators for photonic radiometers\n. Proceedings of the Te Whai Ao Dodd-Walls Centre (DWC) Symposium. (pp. 26). Retrieved from https://www.otago.ac.nz/dodd-walls
Qureshi, P. C., Ng, V., Azeem, F., Trainor, L. S., Schwefel, H. G. L., Coen, S., … Murdoch, S. G. (2023). Tunable multimode dual combs in a Kerr microresonator\n. Proceedings of the Te Whai Ao Dodd-Walls Centre (DWC) Symposium. (pp. 21). Retrieved from https://www.otago.ac.nz/dodd-walls
2022
Journal - Research Article
Christensen, J. T., Azeem, F., Trainor, L. S., Strekalov, D. V., & Schwefel, H. G. L. (2022). Distance calibration via Newton's rings in yttrium lithium fluoride whispering gallery mode resonators. Optics Letters, 47(23), 6053-6056. doi: 10.1364/OL.474539
Qureshi, P. C., Ng, V., Azeem, F., Trainor, L. S., Schwefel, H. G. L., Coen, S., … Murdoch, S. G. (2022). Soliton linear-wave scattering in a Kerr microresonator. Communications Physics, 5, 123. doi: 10.1038/s42005-022-00903-5
Azeem, F., Trainor, L. S., Gao, A., Isarov, M., Strekalov, D. V., & Schwefel, H. G. L. (2022). Ultra-low threshold titanium-doped sapphire whispering-gallery laser. Advanced Optical Materials, 10, 2102137. doi: 10.1002/adom.202102137
Conference Contribution - Published proceedings: Abstract
Ng, V., Qureshi, P., Azeem, F., Trainor, L. S., Schwefel, H. G. L., Coen, S., … Murdoch, S. G. (2022). Intermodal four-wave mixing in MgF2 microresonators enable ultra-wide frequency Generation. Proceedings of the Conference on Lasers and Electro-Optics (CLEO): QELS Fundamental Science. FW1B.5. Retrieved from https://opg.optica.org/abstract.cfm?uri=CLEO_QELS-2022-FW1B.5
Qureshi, P. C., Ng, V., Azeem, F., Trainor, L. S., Schwefel, H. G. L., Coen, S., … Murdoch, S. G. (2022). Nonlinear scattering of dissipative solitons in a Kerr microresonator. Proceedings of the Conference on Lasers and Electro-Optics (CLEO): QELS Fundamental Science. FW1B.3. Retrieved from https://opg.optica.org/abstract.cfm?uri=CLEO_QELS-2022-FW1B.3
Azeem, F., Trainor, L. S., Gao, A., Isarov, M., Strekalov, D. V., & Schwefel, H. G. L. (2022). Observance of lasing and amplification in the first titanium doped sapphire whispering-gallery laser. Proceedings of the Conference on Lasers and Electro-Optics (CLEO): Science and Innovations. SF3I.4. Retrieved from https://opg.optica.org/abstract.cfm?uri=CLEO_SI-2022-SF3I.4
Suresh, M. I., Platt, L., Vogt, D. W., & Schwefel, H. G. L. (2022). Photonic radiometers for CubeSat monitoring of greenhouse gases. Proceedings of the Dodd-Walls Centre Dunedin Symposium. Retrieved from https://www.doddwalls.ac.nz/events
Qureshi, P. C., Ng, V., Azeem, F., Trainor, L., Schwefel, H., Coen, S., … Murdoch, S. G. (2022). Nonlinear scattering of a cavity soliton in a Kerr microresonator. Proceedings of the Dodd-Walls Centre Dunedin Symposium. Retrieved from https://www.doddwalls.ac.nz/events
Lambert, N. J., Schumer, A., Longdell, J. J., Rotter, S., & Schwefel, H. G. L. (2022). Control of magnon polaritons using rapid adiabatic passage and exceptional points. Proceedings of the Dodd-Walls Centre Dunedin Symposium. Retrieved from https://www.doddwalls.ac.nz/events
Christensen, J., Azeem, F., Strekalov, D. V., & Schwefel, H. G. L. (2022). Distance calibration via Newton's rings in the first high-Q yttrium lithium fluoride whispering gallery mode resonator. Proceedings of the Dodd-Walls Centre Dunedin Symposium. Retrieved from https://www.doddwalls.ac.nz/events
2021
Journal - Research Article
Mobassem, S., Lambert, N. J., Rueda, A., Fink, J. M., Leuchs, G., & Schwefel, H. G. L. (2021). Thermal noise in electro-optic devices at cryogenic temperatures. Quantum Science & Technology, 6, 045005. doi: 10.1088/2058-9565/ac0f36
Azeem, F., Trainor, L. S., Devane, P. A., Norman, D. S., Rueda, A., Lambert, N. J., Kumari, M., … Schwefel, H. G. L. (2021). Dielectric perturbations: Anomalous resonance frequency shifts in optical resonators. Optics Letters, 46(10), 2477-2480. doi: 10.1364/OL.420791
Denys, M. D. E., Olsen, M. K., Trainor, L. S., Schwefel, H. G. L., & Bradley, A. S. (2021). Steady states, squeezing, and entanglement in intracavity triplet down conversion. Optics Communications, 484, 126699. doi: 10.1016/j.optcom.2020.126699
Journal - Research Other
Lambert, N. J., & Schwefel, H. G. L. (2021). Visualising the heart of chaos. Light, 10(1), 214. doi: 10.1038/s41377-021-00656-w
Conference Contribution - Published proceedings: Abstract
Azeem, F., Trainor, L. S., Strekalov, D. V., & Schwefel, H. G. L. (2021). Optical parametric oscillation (OPO) in crystalline whispering-gallery mode resonators. Proceedings of the New Zealand Institute of Physics (NZIP) & Physikos Conference. Retrieved from https://confer.eventsair.com/nzip2021/
Mobassem, S., Lambert, N. J., Rueda, A., Fink, J. M., Leuchs, G., & Schwefel, H. G. L. (2021). Thermal noise and fidelity in electro-optic devices. Proceedings of the New Zealand Institute of Physics (NZIP) & Physikos Conference. Retrieved from https://confer.eventsair.com/nzip2021/
Azeem, F., Trainor, L. S., Isarov, M., Kumari, M., Strekalov, D. V., & Schwefel, H. G. L. (2021). Low-threshold lasing in Ti:sapphire whispering-gallery laser. Proceedings of the New Zealand Institute of Physics (NZIP) & Physikos Conference. Retrieved from https://confer.eventsair.com/nzip2021/
2020
Journal - Research Article
Hease, W., Rueda, A., Sahu, R., Wulf, M., Arnold, G., Schwefel, H. G. L., & Fink, J. M. (2020). Bidirectional electro-optic wavelength conversion in the quantum ground state. PRX Quantum, 1, 020315. doi: 10.1103/PRXQuantum.1.020315
Shafiee, G., Strekalov, D. V., Otterpohl, A., Sedlmeir, F., Schunk, G., Vogl, U., Schwefel, H. G. L., … Marquardt, C. (2020). Nonlinear power dependence of the spectral properties of an optical parametric oscillator below threshold in the quantum regime. New Journal of Physics, 22, 073045. doi: 10.1088/1367-2630/ab9a87
Lambert, N. J., Esmail, A. A., Edwards, M., Ferguson, A. J., & Schwefel, H. G. L. (2020). Random telegraph signal analysis with a recurrent neural network. Physical Review E: Statistical, Nonlinear, & Soft Matter Physics, 102, 012312. doi: 10.1103/PhysRevE.102.012312
Hendry, I., Trainor, L. S., Xu, Y., Coen, S., Murdoch, S. G., Schwefel, H. G. L., & Erkintalo, M. (2020). Experimental observation of internally pumped parametric oscillation and quadratic comb generation in a χ2 whispering-gallery-mode microresonator. Optics Letters, 45(5), 1204-1207. doi: 10.1364/OL.385751
Journal - Research Other
Lambert, N. J., Rueda, A., Sedlmeir, F., & Schwefel, H. G. L. (2020). Coherent conversion between microwave and optical photons: An overview of physical implementations [Progress report]. Advanced Quantum Technologies, 3(1), 1900077. doi: 10.1002/qute.201900077
Conference Contribution - Published proceedings: Full paper
Wasiak, M., Botello, G. S., Abdalmalak, K. A., Sedlmeir, F., Rueda, A., Segovia-Vargas, D., Schwefel, H. G. L., & García-Muñoz, L. E. (2020). Compact millimeter and submillimeter-wave photonic radiometer for cubesats. Proceedings of the 14th European Conference on Antennas and Propagation (EuCAP). IEEE. doi: 10.23919/EuCAP48036.2020.9135962
Sayson, N. L. B., Bi, T., Ng, V., Pham, H., Trainor, L. S., Schwefel, H. G. L., … Murdoch, S. G. (2020). Large-frequency-shift tunable parametric oscillation in a Kerr microresonator. Proceedings of the Conference on Lasers and Electro-Optics (CLEO). IEEE. [Full Paper]
Hendry, I., Trainor, L. S., Xu, Y., Coen, S., Murdoch, S. G., Schwefel, H. G. L., & Erkintalo, M. (2020). Observation of internally-pumped parametric oscillation and initial stages of χ(2) comb generation in a lithium niobate microresonator. Proceedings of the Conference on Lasers and Electro-Optics (CLEO). FTh3J.8. IEEE. doi: 10.1364/CLEO_QELS.2020.FTh3J.8
Working Paper; Discussion Paper; Technical Report
Azeem, F., Trainor, L. S., Devane, P. A., Norman, D., Rueda, A., Lambert, N. J., Kumari, M., … Schwefel, H. G. L. (2020). Dielectric perturbations: Anomalous resonance frequency shifts in optical resonators. arXiv. Retrieved from https://arxiv.org/abs/2012.12446
Mobassem, S., Lambert, N. J., Rueda, A., Fink, J. M., Leuchs, G., & Schwefel, H. G. L. (2020). Thermal noise in electro-optic devices at cryogenic temperatures. arXiv. Retrieved from https://arxiv.org/abs/2008.08764
Hease, W., Rueda, A., Sahu, R., Wulf, M., Arnold, G., Schwefel, H. G. L., & Fink, J. M. (2020). Cavity quantum electro-optics: Microwave-telecom conversion in the quantum ground state. arXiv. Retrieved from https://arxiv.org/abs/2005.12763
Lambert, N. J., Esmail, A. A., Edwards, M., Ferguson, A. J., & Schwefel, H. G. L. (2020). Random telegraph signal analysis with a recurrent neural network. arXiv. Retrieved from https://arxiv.org/abs/2002.05817
2019
Journal - Research Article
Otterpohl, A., Sedlmeir, F., Vogl, U., Dirmeier, T., Shafiee, G., Schunk, G., … Schwefel, H. G. L., … Marquardt, C. (2019). Squeezed vacuum states from a whispering gallery mode resonator. Optica, 6(11), 1375-1380. doi: 10.1364/OPTICA.6.001375
Sayson, N. L. B., Bi, T., Ng, V., Pham, H., Trainor, L. S., Schwefel, H. G. L., … Murdoch, S. G. (2019). Octave-spanning tunable parametric oscillation in crystalline Kerr microresonators. Nature Photonics, 13, 701-706. doi: 10.1038/s41566-019-0485-4
Rueda, A., Sedlmeir, F., Kumari, M., Leuchs, G., & Schwefel, H. G. L. (2019). Resonant electro-optic frequency comb. Nature, 568, 378-381. doi: 10.1038/s41586-019-1110-x
Vogt, D. W., Jones, A. H., Schwefel, H. G. L., & Leonhardt, R. (2019). Anomalous blue-shift of terahertz whispering-gallery modes via dielectric and metallic tuning. Optics Letters, 44(6), 1319-1322. doi: 10.1364/OL.44.001319
Conference Contribution - Published proceedings: Full paper
Erkintalo, M., Sayson, N., Bi, T., Ng, V., Pham, H., Trainor, L. S., Schwefel, H. G. L., … Murdoch, S. G. (2019). Octave-spanning tunable parametric oscillation in crystalline Kerr microresonators. Proceedings of the Nonlinear Optics (NLO) Conference. NM2A.4. Washington, DC: Optical Society of America. doi: 10.1364/NLO.2019.NM2A.4
Rueda, A., Sedlmeir, F., Leuchs, G., Kuamri, M., & Schwefel, H. G. L. (2019). Electro-optic frequency comb generation in lithium niobate whispering gallery mode resonators. Proceedings of the Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC). IEEE. doi: 10.1109/CLEOE-EQEC.2019.8873300
Bi, T., Sayson, N. L. B., Ng, V., Trainor, L. S., Schwefel, H. G. L., Coen, S., … Murdoch, S. G. (2019). Continuous tunability of a microresonator parametric oscillator. Proceedings of the Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC). IEEE. doi: 10.1109/CLEOE-EQEC.2019.8872580
Sayson, N. L. B., Bi, T., Ng, V., Pham, H., Trainor, L. S., Schwefel, H. G. L., … Murdoch, S. G. (2019). Wideband tunability of kerr parametric oscillation in an MgF2 microresonator. Proceedings of the Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC). IEEE. doi: 10.1109/CLEOE-EQEC.2019.8871691
Conference Contribution - Published proceedings: Abstract
Hendry, I., Trainor, L., Schwefel, H., Murdoch, S., & Erkintalo, M. (2019). Experimental observation of internally-pumped parametric oscillation in a lithium niobate microresonator. Proceedings of the 12th Annual Dodd-Walls Centre Symposium. (pp. 60). Retrieved from https://www.otago.ac.nz/dodd-walls
Vogt, D. W., Jones, A. H., Schwefel, H. G. L., & Leonhardt, R. (2019). Two octaves spanning high-Q terahertz whispering-gallery modes. Proceedings of the 12th Annual Dodd-Walls Centre Symposium. (pp. 57). Retrieved from https://www.otago.ac.nz/dodd-walls
Mobbasem, S., Azeem, F., Kumari, M., Rueda, A., Sedlmeir, F., & Schwefel, H. G. L. (2019). Electro-optic microwave to optical photon conversion. Proceedings of the 12th Annual Dodd-Walls Centre Symposium. (pp. 47). Retrieved from https://www.otago.ac.nz/dodd-walls
Gao, A., Azeem, F., Denys, M., & Schwefel, H. G. L. (2019). Ti:Sapphire whispering gallery mode resonators. Proceedings of the 12th Annual Dodd-Walls Centre Symposium. (pp. 34). Retrieved from https://www.otago.ac.nz/dodd-walls
Lambert, N., Mobbasem, S., Azeem, F., Kumari, M., Rueda, A., Sedlmeir, F., … Schwefel, H. G. L. (2019). Resonantly enhanced microwave up-conversion. Proceedings of the 12th Annual Dodd-Walls Centre Symposium. (pp. 26). Retrieved from https://www.otago.ac.nz/dodd-walls
Rueda, A., Sedlmeir, F., Leuchs, G., Kumari, M., & Schwefel, H. G. L. (2019). Resonant electro-optic frequency comb generation in lithium niobate whispering gallery mode resonators. Proceedings of the 12th Annual Dodd-Walls Centre Symposium. (pp. 23). Retrieved from https://www.otago.ac.nz/dodd-walls
Sayson, N. L. B., Pham, H., Bi, T., Webb, K. E., Ng, V., Trainor, L. S., Schwefel, H. G. L., … Murdoch, S. G. (2019). Octave-spanning tunable optical parametric oscillation in magnesium fluoride microresonators. Proceedings of the 12th Annual Dodd-Walls Centre Symposium. (pp. 9). Retrieved from https://www.otago.ac.nz/dodd-walls
Rueda, A., Sedlmeir, F., Leuchs, G., Kumari, M., & Schwefel, H. G. L. (2019). Resonant electro-optic frequency comb generation in lithium niobate disk resonator inside a microwave cavity [Extended abstract]. Optical Society of America (OSA) Technical Digest: Nonlinear Optics (NLO). NM2A.5. Optical Society of America (OSA). [Abstract]
Conference Contribution - Verbal presentation and other Conference outputs
van Gelder, L., & Schwefel, H. (2019, October). Shedding light on the distant past: How quantum physics supports prehistoric archaeology. Verbal presentation at the New Zealand Conservators of Cultural Materials (NZCCM) National Conference, Christchurch, New Zealand.
Working Paper; Discussion Paper; Technical Report
Hendry, I., Trainor, L. S., Xu, Y., Coen, S., Murdoch, S. G., Schwefel, H. G. L., & Erkintalo, M. (2019). Experimental observation of internally-pumped parametric oscillation and quadratic comb generation in a χ(2) whispering-gallery-mode microresonator. arXiv. Retrieved from https://arxiv.org/abs/1912.02804
Shafiee, G., Strekalov, D. V., Otterpohl, A., Sedlmeir, F., Schunk, G., Vogl, U., Schwefel, H. G. L., … Marquardt, C. (2019). Nonlinear power dependence of the spectral properties of an optical parametric oscillator below threshold in the quantum regime. arXiv. Retrieved from https://arxiv.org/abs/1912.01263
Denys, M. D. E., Olsen, M. K., Trainor, L. S., Schwefel, H. G. L., & Bradley, A. S. (2019). Steady states, squeezing, and entanglement in intracavity triplet down conversion. arXiv. Retrieved from https://arxiv.org/abs/1907.09572
Rueda, A., Sedlmeir, F., Leuchs, G., Kumari, M., & Schwefel, H. G. L. (2019). Resonant electro-optic frequency comb (v2). arXiv. Retrieved from https://arxiv.org/abs/1808.10608v2
2018
Journal - Research Article
Vogt, D. W., Jones, A. H., Schwefel, H. G. L., & Leonhardt, R. (2018). Prism coupling of high-Q terahertz whispering-gallery-modes over two octaves from 0.2 THz to 1.1 THz. Optics Express, 26(24), 31190-31198. doi: 10.1364/OE.26.031190
Santamaría Botello, G., Sedlmeir, F., Rueda, A., Abdalmalak, K. A., Brown, E. R., Leuchs, G., … Schwefel, H. G. L. (2018). Sensitivity limits of millimeter-wave photonic radiometers based on efficient electro-optic upconverters. Optica, 5(10), 1210-1219. doi: 10.1364/optica.5.001210
Kornienko, V. V., Kitaeva, G. K., Sedlmeir, F., Leuchs, G., & Schwefel, H. G. L. (2018). Towards terahertz detection and calibration through spontaneous parametric down-conversion in the terahertz idler-frequency range generated by a 795 nm diode laser system. APL Photonics, 3(5), 051704. doi: 10.1063/1.5011201
Sayson, N. L. B., Pham, H., Webb, K. E., Ng, V., Trainor, L. S., Schwefel, H. G. L., … Murdoch, S. G. (2018). Origins of clustered frequency combs in Kerr microresonators. Optics Letters, 43(17), 4180-4183. doi: 10.1364/OL.43.004180
Trainor, L. S., Sedlmeir, F., Peuntinger, C., & Schwefel, H. G. L. (2018). Selective coupling enhances harmonic generation of whispering-gallery modes. Physical Review Applied, 9(2), 024007. doi: 10.1103/PhysRevApplied.9.024007
Conference Contribution - Published proceedings: Full paper
Trainor, L. S., Sedlmeir, F., Peuntinger, C., & Schwefel, H. G. L. (2018). Highly efficient polarization-selective out-coupling of harmonic light in birefringent WGM resonators. Proceedings of SPIE (Vol. 10518): Laser Resonators, Microresonators, and Beam Control XX. doi: 10.1117/12.2295863
François, A., Schwefel, H., & Monro, T. M. (2018). Using the lasing threshold in whispering gallery mode resonators for refractive index sensing. Proceedings of SPIE (Vol. 10518): Laser Resonators, Microresonators, and Beam Control XX. 105180V. doi: 10.1117/12.2288871
Conference Contribution - Published proceedings: Abstract
Sayson, N. L. B., Pham, H., Webb, K. E., Ng, V., Trainor, L. S., Schwefel, H. G. L., … Murdoch, S. G. (2018). Broadly tunable optical parametric oscillation in magnesium flouride (MgF2) microresonators. Proceedings of the 11th Annual Dodd-Walls Centre Symposium. (pp. 68). Retrieved from http://www.doddwalls.ac.nz/
Devane, P. A., Kumari, M., Trainor, L. S., & Schwefel, H. G. L. (2018). Frequency shifting whispering gallery modes with planar dielectric substrates. Proceedings of the 11th Annual Dodd-Walls Centre Symposium. (pp. 38). Retrieved from http://www.doddwalls.ac.nz/
Trainor, L. S., & Schwefel, H. G. L. (2018). A third-order down-conversion optical parametric oscillator. Proceedings of the 11th Annual Dodd-Walls Centre Symposium. (pp. 31). Retrieved from http://www.doddwalls.ac.nz/
Halbauer, T., Shafiee, G., Schunk, G., Otterpohl, A., Sedlmeir, F., Strekalov, D., Schwefel, H. G. L., … Marquardt, C. (2018). Towards a whispering gallery mode resonator based wavemeter. Verhandlungen der Deutschen Physikalischen Gesellschaft (DPG). Q51.68. Retrieved from https://www.dpg-physik.de/index.html
Otterpohl, A., Sedlmeir, F., Dirmeier, T., Vogl, U., Schunk, G., Shafiee, G., … Schwefel, H. G. L., … Marquardt, C. (2018). Generation of squeezed vacuum states in a nonlinear crystalline whispering gallery mode resonator. Verhandlungen der Deutschen Physikalischen Gesellschaft (DPG). Q51.60. Retrieved from https://www.dpg-physik.de/index.html
Shafiee, G., Schunk, G., Sedlmeir, F., Otterpohl, A., Vogl, U., Strekalov, D., Schwefel, H. G. L., … Marquardt, C. (2018). Sagnac-type setup for the generation of tunable polarization entangled photon pairs. Verhandlungen der Deutschen Physikalischen Gesellschaft (DPG). Q51.36. Retrieved from https://www.dpg-physik.de/index.html
Schwefel, H. G. L. (2018). Effcient microwave to optical photon conversion: An electro-optical realisation [Invited]. Proceedings of the 2nd CEMS International Symposium on Dynamics in Artificial Quantum Systems (DAQS2018). Mo03. Retrieved from https://www.cems.riken.jp/2018daqs/index.html
Otterpohl, A., Sedlmeir, F., Shafiee, G., Dirmeier, T., Vogl, U., Schunk, G., … Schwefel, H. G. L., … Marquardt, C. (2018). Squeezed vacuum states from a whispering gallery mode resonator. Frontiers in Optics (FiO): Conference Proceedings of OSA's Annual Meeting. FW7B.3. Washington, DC: Optical Society of America. doi: 10.1364/FIO.2018.FW7B.3
Devane, P. A., Kumari, M., Trainor, L. S., & Schwefel, H. G. L. (2018). Frequency shifting whispering gallery modes with planar dielectric substrates. Frontiers in Optics (FiO): Conference Proceedings of OSA's Annual Meeting. JW3A.31. Washington, DC: Optical Society of America. doi: 10.1364/FIO.2018.JW3A.31
Pham, H., Sayson, N. L. B., Webb, K. E., Trainor, L. S., Schwefel, H. G. L., Coen, S., … Murdoch, S. G. (2018). Origin of clustered frequency combs in Kerr microresonators. Proceedings of the Conference on Lasers and Electro-Optics (CLEO). FW3E.2. doi: 10.1364/CLEO_QELS.2018.FW3E.2
Schwefel, H. G. L., Trainor, L. S., Rueda, A., & Sedlhmeir, F. (2018). Nonlinear and quantum optics within whispering gallery mode resonators. Proceedings of the Conference on Lasers and Electro-Optics (CLEO). FTh1E.1. doi: 10.1364/CLEO_QELS.2018.FTh1E.1
Sayson, N. L. B., Pham, H., Webb, K. E., Trainor, L. S., Schwefel, H. G. L., Coen, S., … Murdoch, S. G. (2018). Widely-tunable optical parametric oscillation in MgF2 microresonators. Proceedings of the Conference on Lasers and Electro-Optics (CLEO). SM2D.2. doi: 10.1364/CLEO_SI.2018.SM2D.2
Conference Contribution - Poster Presentation (not in published proceedings)
Rueda, A., Sedlmeir, F., Mobassem, S., Kumari, M., & Schwefel, H. G. L. (2018, December). Frequency comb generation using lithium niobate whispering gallery mode resonators. Poster session presented at the IONS Conference on Optics, Atoms, and Laser Applications (KOALA), Sydney, Australia.
Gao, A., Azeem, F., Dens, M., & Schwefel, H. G. L. (2018, December). Titanium-doped sapphire whispering gallery mode resonators. Poster session presented at the IONS Conference on Optics, Atoms, and Laser Applications (KOALA), Sydney, Australia.
Conference Contribution - Verbal presentation and other Conference outputs
Schwefel, H. (2018, May). Asymmetric crystalline cavities for flexible non-linear optics. Invited presentation at the 2nd International Workshop on Asymmetric Microcavity and Wave Chaos, Fuzhou, China.
Working Paper; Discussion Paper; Technical Report
Rueda, A., Sedlmeir, F., Leuchs, G., Kumari, M., & Schwefel, H. G. L. (2018). Resonant electro-optic frequency comb. arXiv. Retrieved from https://arxiv.org/abs/1808.10608
2017
Journal - Research Article
Sedlmeir, F., Foreman, M. R., Vogl, U., Zeltner, R., Schunk, G., Strekalov, D. V., … Schwefel, H. G. L. (2017). Polarization-selective out-coupling of whispering-gallery modes. Physical Review Applied, 7(2), 024029. doi: 10.1103/PhysRevApplied.7.024029
Journal - Research Other
Ge, L., Feng, L., & Schwefel, H. G. L. (2017). Optical microcavities: New understandings and developments. Photonics Research, 5(6), OM1-OM3. doi: 10.1364/PRJ.5.000OM1
Conference Contribution - Published proceedings: Full paper
Botello, G. S., Abdalmalak, K. A., Schlecht, M.-T., González-Overjero, M.-T., Sedlmeir, F., Schwefel, H. G. L., … Muñoz, L.-E. G. (2017). Analytical study of free-space coupling of THz radiation for a new radioastronomy receiver concept. Proceedings of the 11th European Conference on Antennas and Propagation (EUCAP). (pp. 836-840). doi: 10.23919/EuCAP.2017.7928481
Conference Contribution - Published proceedings: Abstract
Rueda, A., Sedlmeir, F., Collodo, M. C., Vogl, U., Stiller, B., Schunk, G., … Schwefel, H. G. L. (2017). Single sideband microwave to optical photon conversion-an electro-optic realization. Proceedings of the Nonlinear Optics Conference. NM3A.1. doi: 10.1364/NLO.2017.NM3A.1
Trainor, L. S., Sedlmeir, F., Peuntinger, C., & Schwefel, H. G. L. (2017). Broadband second harmonic generation in whispering gallery mode resonators enhanced by polarization selective out-coupling. Proceedings of the Nonlinear Optics Conference. NM3A.2. OSA. doi: 10.1364/NLO.2017.NM3A.2
Trainor, L. S., Peuntinger, C., Sedlmeir, F., & Schwefel, H. G. L. (2017). Harmonic generation in a birefringent whispering gallery mode resonator. Proceedings of the 10th Annual Dodd-Walls Symposium. (pp. 39). Retrieved from http://www.doddwalls.ac.nz/
Schwefel, H. G. L., Erkintalo, M., & Coen, S. (2017). Optical resonators for linear and nonlinear interactions [Workshop]. Proceedings of the 10th Annual Dodd-Walls Symposium. (pp. 11). Retrieved from http://www.doddwalls.ac.nz/
Rueda, A., Sedlmeir, F., Collodo, M. C., Vogl, U., Stiller, B., Schunk, G., … Schwefel, H. G. L. (2017). Efficient microwave to optical photon conversion: An electro-optical realisation [Invited]. Proceedings of the 47th Winter Colloquium on the Physics of Quantum Electronics (PQE). (pp. 309). Retrieved from http://www.pqeconference.com/pqe2017/
2016
Journal - Research Article
Santamaría-Botello, G. A., García Muñoz, L. E., Sedlmeir, F., Preu, S., Segovia-Vargas, D., Atia Abdalmalak, K., … Schwefel, H. G. L., & Weber, H. B. (2016). Maximization of the optical intra-cavity power of whispering-gallery mode resonators via coupling prism. Optics Express, 24(23), 26503-26514. doi: 10.1364/OE.24.026503
Strekalov, D. V., Marquardt, C., Matsko, A. B., Schwefel, H. G. L., & Leuchs, G. (2016). Nonlinear and quantum optics with whispering gallery resonators. Journal of Optics, 18, 123002. doi: 10.1088/2040-8978/18/12/123002
Foreman, M. R., Sedlmeir, F., Schwefel, H. G. L., & Leuchs, G. (2016). Dielectric tuning and coupling of whispering gallery modes using an anisotropic prism. Journal of the Optical Society of America B, 33(11), 2177-2195. doi: 10.1364/JOSAB.33.002177
Rueda, A., Sedlmeir, F., Collodo, M. C., Vogl, U., Stiller, B., Schunk, G., … Schwefel, H. G. L. (2016). Efficient microwave to optical photon conversion: An electro-optical realization. Optica, 3(6), 597-604. doi: 10.1364/OPTICA.3.000597
Schunk, G., Vogl, U., Sedlmeir, F., Strekalov, D. V., Otterpohl, A., Averchenko, V., Schwefel, H. G. L., … Marquardt, C. (2016). Frequency tuning of single photons from a whispering-gallery mode resonator to MHz-wide transitions. Journal of Modern Optics, 63(20), 2058-2073. doi: 10.1080/09500340.2016.1148211
Conference Contribution - Published proceedings: Full paper
Santamaría-Bortello, G., Rivera-Lavado, A., Preu, S., Sedlmeir, F., Lioubtchenko, D., Schwefel, H., … García Muñoz, L. E. (2016). Sub-THz photon counting receiver working at room temperature for polarization measurements of the cosmic microwave background radiation. Proceedings of the 10th European Conference on Antennas and Propagation (EuCAP). IEEE. doi: 10.1109/EuCAP.2016.7481288
Conference Contribution - Published proceedings: Abstract
Schunk, G., Shafiee, G., Vogl, U., Strekalov, D. V., Förtsch, M., Otterpohl, A., Sedlmeir, F., Schwefel, H. G. L., … Marquardt, C. (2016). Interfacing atomic transitions with single photons [Invited]. Proceedings of the 25th Annual International Laser Physics Workshop. Retrieved from http://www.lasphys.com/workshops/lasphys16/
Rueda, A. R., Sedlmeir, F., & Schwefel, H. G. L. (2016). Electro-opical modulator with 0.1% quantum efficiency. Proceedings of the 4th Advanced Electromagnetics Symposium (AES). Retrieved from http://mysymposia.org/index.php/AES17/AES16
Rueda, A., Sedlmeir, F., Collodo, M. C., Vogl, U., Stiller, B., Schunk, G., … Schwefel, H. G. L. (2016). Nonlinear single sideband microwave to optical conversion using an electro-optic WGM-resonator. Proceedings of the Photonics and Fiber Technology Congress. NTh3A.6. doi: 10.1364/NP.2016.NTh3A.6
Sedlmeir, F., Rueda, A., Preu, S., García-Muñoz, L. E., & Schwefel, H. G. L. (2016). Efficient and coherent conversion of 80 GHz signals into the optical domain using a nonlinear whispering gallery mode resonator. Proceedings of the Photonics and Fiber Technology Congress. NTh3A.4. doi: 10.1364/NP.2016.NTh3A.4
Peuntinger, C., Trainor, L., Sedlmeir, F., Hauer, M., Strekalov, D. V., & Schwefel, H. G. L. (2016). Third harmonic generation in birefringent WGM Resonators: A survey of possible geometries. Proceedings of the Photonics and Fiber Technology Congress. JT4A.24. doi: 10.1364/ACOFT.2016.JT4A.24
Schunk, G., Shafiee, G., Vogl, U., Strekalov, D., Otterpohl, A., Sedlmeir, F., Schwefel, H. G. L., … Marquardt, C. (2016). Towards two-photon interference with a whispering gallery photon pair source. Proceedings of the Photonics and Fiber Technology Congress. NTh2A.5. doi: 10.1364/NP.2016.NTh2A.5
Schunk, G., Shafiee, G., Vogl, U., Strekalov, D., Otterpohl, A., Soltani, N., Sedlmeir, F., Schwefel, H. G. L., … Marquardt, C. (2016). Two-photon interference with a non-degenerate photon-pair source. Verhandlungen der Deutschen Physikalischen Gesellschaft (DPG). (pp. 78). Retrieved from https://www.dpg-physik.de/veroeffentlichung/verhandlungen/
Otterpohl, A., Schunk, G., Vogl, U., Sedlmeir, F., Shafiee, G., Strekalov, D., … Schwefel, H. G. L., … Marquardt, C. (2016). Towards and beyond squeezed vacuum states in a nonlinear crystalline whispering gallery mode resonator. Verhandlungen der Deutschen Physikalischen Gesellschaft (DPG). (pp. 79-80). Retrieved from https://www.dpg-physik.de/veroeffentlichung/verhandlungen/
Rueda, A., Sedlmeir, F., Collodo, M. C., Vogl, U., Stiller, B., Schunk, G., … Schwefel, H. G. L. (2016). Efficient single sideband microwave to optical conversion using a LiNbO3 WGM-resonator. Proceedings of the Conference on Lasers and Electro-Optics (CLEO). SF2G.3. doi: 10.1364/CLEO_SI.2016.SF2G.3
Sedlmeir, F., Rueda, A., Preu, S., García-Muñoz, L. E., & Schwefel, H. G. L. (2016). Efficient up-conversion of weak THz signals into the optical domain using a whispering gallery mode resonator. Proceedings of the Conference on Lasers and Electro-Optics (CLEO). STh1I.6. doi: 10.1364/CLEO_SI.2016.STh1I.6
Schwefel, H. G. L., Rueda, A., & Sedlmeir, F. (2016). Efficient microwave to optical photon conversion: An electro-optical approach. In M. Andersen & A. Deb (Eds.), Proceedings of the 9th Annual Dodd-Walls Symposium. (pp. 24). Retrieved from http://www.doddwalls.ac.nz/wawcs0138456/Symposium.html
Sedlmeir, F., Peuntinger, C., Hauer, M., & Schwefel, H. G. L. (2016). Third harmonic generation in Birefringent WGM resonators. In A. B. Deb & N. Kjærgaard (Eds.), Proceedings of the Matariki Workshop on Quantum Science. (pp. 61). Retrieved from http://quantum.otago.ac.nz/mqs2016.html
Rueda, A., Sedlmeir, F., Collodo, M. C., Vogl, U., Stiller, B., Schunk, G., … Schwefel, H. G. L. (2016). Efficient single sideband microwave to optical conversion using a nonlinear WGM-resonator. In A. B. Deb & N. Kjærgaard (Eds.), Proceedings of the Matariki Workshop on Quantum Science. (pp. 36). Retrieved from http://quantum.otago.ac.nz/mqs2016.html
Schwefel, H. G. L., Rueda, A., & Sedlmeir, F. (2016). Coherent up-conversion of microwave & THz radiation into the telecom regime: Towards the fundamental limit. In A. B. Deb & N. Kjærgaard (Eds.), Proceedings of the Matariki Workshop on Quantum Science. (pp. 25). Retrieved from http://quantum.otago.ac.nz/mqs2016.html
Conference Contribution - Poster Presentation (not in published proceedings)
Rueda, A., Sedlmeir, F., Collodo, M. C., Vogl, U., Stiller, B., Fink, J., … Schwefel, H. G. L. (2016, June-July). Efficient single sideband microwave to optical conversion using a LiNbO3 WGM-resonator. Poster session presented at the 23rd Central European Workshop on Quantum Optics, Kolymbari, Greece.
2015
Chapter in Book - Research
Damm, C., Schwefel, H. G. L., Sedlmeir, F., Hartnagel, H., Preu, S., & Weickhmann, C. (2015). Selected emerging THz technologies. In G. Carpintero, L. García Muñoz, H. Hartnagel, S. Preu & A. Räisänen (Eds.), Semiconductor terahertz technology: Devices and systems at room temperature operation. (pp. 340-382). Chichester, UK: Wiley.
Journal - Research Article
Förtsch, M., Schunk, G., Fürst, J. U., Strekalov, D., Gerrits, T., Stevens, M. J., Sedlmeir, F., Schwefel, H. G. L., … Marquardt, C. (2015). Highly efficient generation of single-mode photon pairs from a crystalline whispering-gallery-mode resonator source. Physical Review A, 91, 023812. doi: 10.1103/PhysRevA.91.023812
Förtsch, M., Gerrits, T., Stevens, M. J., Strekalov, D., Schunk, G., Fürst, J. U., … Sedlmeir, F., Schwefel, H. G. L., … Marquardt, C. (2015). Near-infrared single-photon spectroscopy of a whispering gallery mode resonator using energy-resolving transition edge sensors. Journal of Optics, 17, 065501. doi: 10.1088/2040-8978/17/6/065501
Rivera-Lavado, A., Preu, S., García-Muñoz, L. E., Generalov, A., Montero-de-Paz, J., Döhler, G., … Sedlmeir, F., … Schwefel, H. G. L., … Räisänen, A. V. (2015). Dielectric rod waveguide antenna as THz emitter for photomixing devices. IEEE Transactions on Antennas & Propagation, 63(3), 882-890. doi: 10.1109/TAP.2014.2387419
Peano, V., Schwefel, H. G. L., Marquardt, C., & Marquardt, F. (2015). Intracavity squeezing can enhance quantum-limited optomechanical position detection through deamplification. Physical Review Letters, 115(24), 243603. doi: 10.1103/PhysRevLett.115.243603
Schunk, G., Vogl, U., Strekalov, D. V., Förtsch, M., Sedlmeir, F., Schwefel, H. G. L., … Marquardt, C. (2015). Interfacing transitions of different alkali atoms and telecom bands using one narrowband photon pair source. Optica, 2(9), 773-778. doi: 10.1364/OPTICA.2.000773
Journal - Research Other
Schwefel, H. G. L., & Türeci, H. (2015). A chaotic approach clears up imaging: A laser that emits bright, incoherent light provides an ideal light source for imaging [Perspective]. Science, 348(6231), 189-190. doi: 10.1126/science.aaa7409
Conference Contribution - Published proceedings: Abstract
Schunk, G., Vogl, U., Förtsch, M., Strekalov, D., Sedlmeir, F., Schwefel, H. G. L., … Marquardt, C. (2015). Adressing Rb and Cs atomic transitions with single tunable narrowband photon-pair source. Proceedings of the 45th Winter Colloquium on the Physics of Quantum Electronics (PQE). (pp. 215). Retrieved from http://www.pqeconference.com/pqe2015/
Sedlmeir, F., Rueda, A., Schneidereit, M. F., Preu, S., Mendéz-Aller, M., Räisänen, A. V., … Schwefel, H. G. L. (2015). Efficient up- and down conversion of microwave signals into the optical regime using whispering gallery mode resonators. Proceedings of the 45th Winter Colloquium on the Physics of Quantum Electronics (PQE). (pp. 267). Retrieved from http://www.pqeconference.com/pqe2015/index.shtml
Schwefel, H. G. L. (2015). Nonlinear frequency conversion in WGM resonators. Proceedings of the 45th Winter Colloquium on the Physics of Quantum Electronics (PQE). (pp. 263). Retrieved from http://www.pqeconference.com/pqe2015/
Schunk, G., Vogl, U., Förtsch, M., Strekalov, D., Sedlmeir, F., Schwefel, H. G. L., … Marquardt, C. (2015). Addressing Rb and Cs transitions with a tunable source of photon pairs. Proceedings of the Joint European Conference on Lasers and Electro-Optics and European Quantum Electronics Conference. EB 3.1. Retrieved from https://www.osapublishing.org/conference.cfm?meetingid=90&yr=2015
Leuchs, G., Marquardt, C., & Schwefel, H. G. L. (2015). Nonlinear quantum optics in a milimeter size whispering gallery mode resonator. Proceedings of the Nonlinear Optics Conference. NW2A.5. doi: 10.1364/NLO.2015.NW2A.5
Sedlmeir, F., Zeltner, R., Leuchs, G., & Schwefel, H. G. L. (2015). Small refractive index, high performance: Magnesium fluoride whispering gallery mode resonators for refractometric sensing. Proceedings of the Joint European Conference on Lasers and Electro-Optics and European Quantum Electronics Conference. Retrieved from https://www.osapublishing.org/conference.cfm?meetingid=90&yr=2015
2014
Journal - Research Article
Zeltner, R., Sedlmeir, F., Leuchs, G., & Schwefel, H. G. L. (2014). Crystalline MgF2 whispering gallery mode resonators for enhanced bulk index sensitivity. European Physical Journal Special Topics, 223, 1989-1994. doi: 10.1140/epjst/e2014-02241-8
Schunk, G., Fürst, J. U., Förtsch, M., Strekalov, D. V., Vogl, U., Sedlmeir, F., Schwefel, H. G. L., … Marquardt, C. (2014). Identifying modes of large whispering-gallery mode resonators from the spectrum and emission pattern. Optics Express, 22(25), 30795-30806. doi: 10.1364/OE.22.030795
Sedlmeir, F., Zeltner, R., Leuchs, G., & Schwefel, H. G. L. (2014). High-Q MgF2 whispering gallery mode resonators for refractometric sensing in aqueous environments. Optics Express, 22(25), 30934-30942. doi: 10.1364/OE.22.030934
Collodo, M. C., Sedlmeir, F., Sprenger, B., Svitlov, S., Wang, L., Schwefel, H. G. L., & Wang, L. J. (2014). Sub-kHz lasing of a CaF2 whispering gallery mode resonator stabilized fiber ring laser. Optics Express, 22(16), 19277-19283. doi: 10.1364/OE.22.01914119277
Journal - Research Other
Vollmer, F., & Schwefel, H. G. L. (2014). Taking detection to the limit with optical microcavities: Recent advances presented at the 560. WE Heraeus Seminar. European Physical Journal Special Topics, 223, 1907-1916. doi: 10.1140/epjst/e2014-02271-2
Schwefel, H. G. L. (2014). In optical pumping, less can be more: Creating loss in one optical resonator can initiate lasing in its coupled partner [Perspective]. Science, 346(6207), 304-305. doi: 10.1126/science.1260707
Conference Contribution - Published proceedings: Abstract
Schunk, G., Vogl, U., Förtsch, M., Strekalov, D. V., Sedlmeir, F., Schwefel, H. G. L., … Marquardt, C. (2014). Interfacing various atomic transitions and telecom wavelengths with a single tunable narrowband photon-pair source. Proceedings of the 12th International Conference on Quantum Communication, Measurement and Computing (QCMC). B79, (pp. 61). Retrieved from http://qcmc2014.ustc.edu.cn/
Förtsch, M., Schunk, G., Fürst, J., Sedlmeir, F., Strekalov, D. V., Schwefel, H. G. L., … Marquardt, C. (2014). Single-mode photon pairs from a crystalline whispering gallery mode resonator. Proceedings of the 12th International Conference on Quantum Communication, Measurement and Computing (QCMC). B28, (pp. 48). Retrieved from http://qcmc2014.ustc.edu.cn/
Schwefel, H. G. L. (2014). Making microwave radiation visible: Phase-matching in non-linear crystalline whispering gallery mode resonators [Invited]. Proceedings of the Progress in Electromagnetic Research Symposium (PIERS). (pp. 503). Retrieved from http://piers.org/piers2014Guangzhou/
Zeltner, R., Sedlmeir, F., Leuchs, G., & Schwefel, H. G. L. (2014). Crystalline MgF2 whispering gallery mode resonators for enhanced bulk index sensitivity. Proceedings of the 560th WE Heraeus Seminar: Taking Detection to the Limit: Biosensing with Optical Microcavities. Retrieved from http://www.vollmerlab.net/workshop.php
Förtsch, M., Schunk, G., Fürst, J. U., Strekalov, D., Sedlmeir, F., Schwefel, H. G. L., … Marquardt, C. (2014). High efficient generation of single mode narrow-band photon pairs. Verhandlungen der Deutschen Physikalischen Gesellschaft (DPG). SYQR4A22.1. Retrieved from https://www.dpg-physik.de/veroeffentlichung/verhandlungen/
Sedlmeir, F., Hauer, M., Fürst, J., Leuchs, G., & Schwefel, H. G. L. (2014). Angle cut, birefrigent whispering gallery mode resonators. Verhandlungen der Deutschen Physikalischen Gesellschaft (DPG). Q 67.4. Retrieved from https://www.dpg-physik.de/veroeffentlichung/verhandlungen/
Schneidereit, M. F., Sedlmeir, F., Preu, S., Raisanen, A. V., García-Muñoz, L. E., Leuchs, G., & Schwefel, H. G. L. (2014). Waveguide coupling of high index whispering gallery mode resonators in the THz domain. Verhandlungen der Deutschen Physikalischen Gesellschaft (DPG). Q 61.7. Retrieved from https://www.dpg-physik.de/veroeffentlichung/verhandlungen/
Schunk, G., Förtsch, M., Fürst, J., Strekalov, D., Sedlmeir, F., Schwefel, H., … Marquardt, C. (2014). Mode spectrum and emission pattern of whispering gallery mode disk resonators. Verhandlungen der Deutschen Physikalischen Gesellschaft (DPG). Q 38.7. Retrieved from https://www.dpg-physik.de/veroeffentlichung/verhandlungen/
Zeltner, R., Sedlmeir, F., Leuchs, G., & Schwefel, H. G. L. (2014). Increasing quality through the surrounding: Whispering gallery mode resonators and their environment. Verhandlungen der Deutschen Physikalischen Gesellschaft (DPG). Q 30.29. Retrieved from https://www.dpg-physik.de/veroeffentlichung/verhandlungen/
Förtsch, M., Schunk, G., Fürst, J., Sedlmeir, F., Strekalov, D., Schwefel, H. G. L., … Marquardt, C. (2014). Highly efficient generation of narrow-band single-mode photon pairs from a whispering gallery mode resonator. Proceedings of the Conference on Lasers and Electro-Optics (CLEO). FW3A.6. doi: 10.1364/CLEO_QELS.2014.FW3A.6
Zeltner, R., Sedlmeir, F., Leuchs, G., & Schwefel, H. G. L. (2014). Refractometric sensing with crystalline MgF2 whispering gallery mode resonators. Proceedings of the Frontiers in Optics Conference. LTh3I.5. doi: 10.1364/LS.2014.LTh3I.5
Sedlmeir, F., Schneidereit, M. F., Preu, S., Mendéz-Aller, M., Räisänen, A. V., García-Muñoz, L. E., … Schwefel, H. G. L. (2014). Sum and difference frequency generation of optical and microwave photons in a whispering gallery mode resonator. Proceedings of the Frontiers in Optics Conference. FM3B.4. doi: 10.1364/FIO.2014.FM3B.4
Conference Contribution - Poster Presentation (not in published proceedings)
Méndez-Aller, M., García-Muñoz, L. E., Schwefel, H. G. L., Sedlmeir, F., Schneidereit, M., Rivera-Lavado, A., & Segovia-Vargas, D. (2014, May). Room temperature receiver based on whispering gallery mode resonators for radio astronomy applications. Poster session presented at the 4th European Optical Society (EOS) Topical Meeting on Terahertz Science & Technology, Camogli, Italy.
Conference Contribution - Verbal presentation and other Conference outputs
Schwefel, H. G. L. (2014, April). Crystalline WGM resonators: Good for sensing? Verbal presentation at the 560th WE Heraeus Seminar: Taking Detection to the Limit: Biosensing with Optical Microcavities, Bad Honnef, Germany.
Hauer, M., Sedlmeir, F., Leuchs, G., & Schwefel, H. G. L. (2014, September). Novel types of nonlinear enhancement in uniaxial crystalline whispering gallery mode resonators. Verbal presentation at the Photon14 Conference, London, UK.
Schwefel, H. (2014, June). Nonlinear optical properties of whispering gallery mode resonators. Verbal presentation at the Extreme and Quantum Photonics Summer School: Ultrafast Lasers and Applications, Ottawa, Canada.
Förtsch, M., Schunk, G., Fürst, J., Sedlmeir, F., Strekalov, D., Schwefel, H. G. L., … Nam, S. W. (2014, July). Narrow-band single-mode photon pairs from a whispering gallery mode resonator. Verbal presentation at the 23rd Annual International Laser Physics (LPHYS) Workshop, Sofia, Bulgaria.
Schunk, G., Förtsch, M., Fürst, J. U., Vogl, U., Strekalov, D. V., Sedlmeir, F., Schwefel, H. G. L., … Marquardt, C. (2014, July). Identifying modes: Frequency spectra and emission patterns of large whispering-gallery mode resonators. Verbal presentation at the 23rd Annual International Laser Physics (LPHYS) Workshop, Sofia, Bulgaria.
2013
Journal - Research Article
Breunig, I., Sturman, B., Sedlmeir, F., Schwefel, H. G. L., & Buse, K. (2013). Whispering gallery modes at the rim of an axisymmetric optical resonator: Analytical versus numerical description and comparison with experiment. Optics Express, 21(25), 30683-30692. doi: 10.1364/OE.21.030683
Sedlmeir, F., Hauer, M., Fürst, J. U., Leuchs, G., & Schwefel, H. G. L. (2013). Experimental characterization of an uniaxial angle cut whispering gallery mode resonator. Optics Express, 21(20), 23942-23949. doi: 10.1364/OE.21.023942
Preu, S., Schmid, S. I., Sedlmeir, F., Evers, J., & Schwefel, H. G. L. (2013). Directional emission of dielectric disks with a finite scatterer in the THz regime. Optics Express, 21(14), 16370-16380. doi: 10.1364/OE.21.016370
Kaplan, A., Tomes, M., Carmon, T., Kozlov, M., Cohen, O., Bartal, G., & Schwefel, H. G. L. (2013). Finite element simulation of a perturbed axial-symmetric whispering-gallery mode and its use for intensity enhancement with a nanoparticle coupled to a microtoroid. Optics Express, 21(12), 14169-14180. doi: 10.1364/OE.21.014169
Conference Contribution - Published proceedings: Full paper
Förtsch, M., Gerrits, T., Stevens, M. J., Fürst, J. U., Schunk, G., Sedlmeir, F., Schwefel, H. G. L., … Marquardt, C. (2013). Near-infrared spectroscopy on a single photon level. Proceedings of the Conference on Lasers and Electro-Optics Pacific Rim. ThG3_1. Retrieved from https://www.osapublishing.org/conferences.cfm
Sedlmeir, F., Hauer, M., Fürst, J. U., Strekalov, D. V., & Schwefel, H. G. L. (2013). Complex polarization states of off-axis uniaxial whispering gallery mode resonators. Proceedings of SPIE (Vol. 8600): Laser Resonators, Microresonators, and Beam Control. 86001B . doi: 10.1117/12.2002434
Conference Contribution - Published proceedings: Abstract
Schwefel, H. G. L., Sedlmeir, F., Fürst, J., Hauer, M., Strekalov, D. V., & Leuchs, G. (2013). Polarization in birefringent WGM resonators [Invited]. Proceedings of the 45th Winter Colloquium on the Physics of Quantum Electronics (PQE). (pp. 213). Retrieved from http://www.pqeconference.com/pqe2015/
Sedlmeir, F., Hauer, M., Fürst, J. U., & Schwefel, H. G. L. (2013). Exploring and exploiting polarization properties of angle cut whispering gallery resonators. Proceedings of the Progress in Electromagnetic Research Symposium (PIERS). (pp. 867). Retrieved from http://piers.org/piers/
Sedlmeir, F., Hauer, M., Fürst, J. U., & Schwefel, H. G. L. (2013). Broad band second harmonic generation in crystalline whispering gallery mode resonators [Invited]. Proceedings of the Progress in Electromagnetic Research Symposium (PIERS). (pp. 505). Retrieved from http://piers.org/piers/
Schunk, G., Förtsch, M., Fürst, J., Strekalov, D., Sedlmeir, F., Schwefel, H., … Leuchs, G. (2013). Wavelength tunability of a triply resonant whispering gallery optical parametric oscillator. Verhandlungen der Deutschen Physikalischen Gesellschaft (DPG). Q 54.4. Retrieved from https://www.dpg-physik.de/veroeffentlichung/verhandlungen/
Evers, J., Schmid, S. I., Preu, S., Sedlmeir, F., Leuchs, G., & Schwefel, H. G. L. (2013). Directional emission of dielectric disks with a finite scatterer in the THz regime. Verhandlungen der Deutschen Physikalischen Gesellschaft (DPG). Q 16.3. Retrieved from https://www.dpg-physik.de/veroeffentlichung/verhandlungen/
Sedlmeir, F., Hauer, M., Fürst, J., Strekalov, D. V., & Schwefel, H. G. L. (2013). Complex polarization in non z-cut whispering gallery mode resonators. Proceedings of the European Conference on Lasers and Electro-Optics Conference. CE_9_3. Retrieved from https://www.osapublishing.org/
Conference Contribution - Verbal presentation and other Conference outputs
Schwefel, H. (2013, November). Crystalline WGM resonators: Linear and non-linear applications from the visible to THz. Invited presentation at the French-Russian-German Laser Symposium, Besançon, France.
2012
Journal - Research Article
Kozlov, M., Kfir, O., Fleischer, A., Kaplan, A., Carmon, T., Schwefel, H. G. L., … Cohen, O. (2012). Narrow-bandwidth high-order harmonics driven by long-duration hot spots. New Journal of Physics, 14, 063036. doi: 10.1088/1367-2630/14/6/063036
Conference Contribution - Published proceedings: Abstract
Sedlmeir, F., Fürst, J., Strekalov, D., Schwefel, H. G. L., & Leuchs, G. (2012). Elliptically polarized whispering gallery modes in uniaxial crystal resonators. Proceedings of the Frontiers in Optics Conference. FTh1E.7. doi: 10.1364/FIO.2012.FTh1E.7
Förtsch, M., Schunk, G., Sedlmeir, F., Fürst, J., Wittmann, C., Strekalov, D., Schwefel, H. G. L., & Marquardt, C. (2012). Widely tunable and compact optical parametric oscillator based on a whispering gallery mode resonator. Verhandlungen der Deutschen Physikalischen Gesellschaft (DPG). Q 40.3. Retrieved from https://www.dpg-physik.de/veroeffentlichung/verhandlungen/
Collodo, M. C., Sprenger, B., Sedlmeir, F., Svitlov, S., Schwefel, H. G. L., & Wang, L. J. (2012). Passive ring-laser stabilization to sub-kHz linewidths with whispering gallery mode resonator. Verhandlungen der Deutschen Physikalischen Gesellschaft (DPG). Q 28.1. Retrieved from https://www.dpg-physik.de/veroeffentlichung/verhandlungen/
Sedlmeir, F., Strekalov, D., Bauerschmidt, S., Preu, S., Malzer, S., Döhler, G., Schwefel, H. G. L., & Leuchs, G. (2012). Towards highly efficient whispering gallery supported THz detection. Verhandlungen der Deutschen Physikalischen Gesellschaft (DPG). Q 54.55. Retrieved from https://www.dpg-physik.de/veroeffentlichung/verhandlungen/
Förtsch, M., Schunk, G., Sedlmeir, F., Fürst, J., Wittmann, C., Strekalov, D., Schwefel, H. G. L., … Leuchs, G. (2012). Mode-hop-free tunable optical parametric oscillator utilizing a whispering gallery mode resonator. Proceedings of the Conference on Lasers and Electro-Optics (CLEO). CW3K.7. doi: 10.1364/CLEO_SI.2012.CW3K.7
Collodo, M., Sprenger, B., Sedlmeir, F., Svitlov, S., Schwefel, H. G. L., & Wang, L. J. (2012). Sub-kHz linewidth of crystalline whispering gallery mode resonator stabilized ring-laser. Proceedings of the Conference on Lasers and Electro-Optics (CLEO). CTh3A.5. doi: 10.1364/CLEO_SI.2012.CTh3A.5
Conference Contribution - Verbal presentation and other Conference outputs
Schwefel, H. G. L., Sedlmeir, F., Strekalov, D. V., Bauerschmidt, S., Preu, S., Malzer, S., … Leuchs, G. (2012, June). Whispering gallery mode resonator based optical up-conversion of THz radiation. Verbal presentation at the 2nd International TERA Conference: Terahertz and Microwave Radiation: Generation, Detection and Applications, Moscow, Russia.