NTNU - Nonlinear Integrated Photonics
Nonlinear Integrated Photonics Group
Research activity
The Nonlinear Integrated Photonics Group at the Department of Electronic Systems builds photonic integrated circuits that generate, amplify and convert light using the intrinsic nonlinear optical properties of novel materials. We design, fabricate and test ultra-low-loss waveguides in emerging platforms such as thin-film lithium tantalate, lithium niobate, III-V and II-VI semiconductors. With them we develop chip-scale optical amplifiers, tunable lasers, frequency combs and quantum light sources. Our aim is to shrink functions that today need an optical table into compact, robust devices for optical communication, sensing, LiDAR and quantum technology.
Optical parametric amplification
Erbium-doped fibre amplifiers carry today's internet, but they cover only a fraction of the fibre's low-loss window, need optical isolators and do not feature quantum limited noise performance. Travelling-wave optical parametric amplifiers use the intrinsic nonlinearity of transparent materials instead. They amplify over very wide bandwidths, in one direction only, and – in phase-sensitive operation – without adding noise.
Our earlier chip-based parametric amplifiers in silicon nitride and gallium phosphide reached net fibre-to-fibre gain in the continuous-wave regime. We now develop amplifiers in thin-film lithium tantalate and III-phosphides that cut the required pump power enough for compact low power device integration.
Key publications:
An ultra-broadband photonic-chip-based parametric amplifier, N. Kuznetsov*, A Nardi*, J. Riemensberger*, A. Davydova, M. Churaev, P. Seidler, T.J. Kippenberg, Nature 639, 928–934 (2025)
A photonic integrated continuous-travelling-wave parametric amplifier, J. Riemensberger, N. Kusnetzov, J. Liu, J. He, R.N. Wang, T.J. Kippenberg, Nature 612, 56–61 (2022),
Quantum light sources and hybrid integrated lasers:
Hybrid integration is the combination of two different chip substrates to combine and enhance the capabilities and performance of integrated photonics. For example by combining an active laser gain medium such as a III-V semiconductor laser and a passive high-Q optical microresonator, we can make low noise and highly frequency agile lasers for applications in metrology, sensing, and quantum technology.
Key Publications:
Ultralow-noise frequency-agile photonic integrated lasers for coherent ranging, G. Lihachev*, J. Riemensberger*, W. Weng*, J. Liu, H. Tian, A. Siddharth, V. Snigirev, R.N. Wang, J. He, S.A. Bhave, T.J. Kippenberg, Nature Communications 13, 1 (2022)
Ultrafast tunable photonic integrated Pockels extended-DBR laser, A. Siddharth, S. Bianconi, R.N. Wang, Z. Qiu, A.S. Voloshin, M.J. Bereyhi, J. Riemensberger, T.J. Kippenberg, Nature Photonics 19, 709-717 (2025)
New material platforms
We look beyond silicon, silicon nitride and lithium niobate for materials with stronger nonlinearity and lower loss. Thin-film lithium tantalate and III-V and II-VI semiconductors offer wider transparency windows, higher power handling capabilities, or much stronger second- and third-order nonlinearities on chip.
We develop waveguide designs and fabrication processes for these materials, extending nonlinear integrated photonics from the visible to the mid-infrared – including new on-chip frequency comb sources, optical parametric oscillators and frequency converters.
Key Publications:
Lithium tantalate photonic integrated circuits for volume manufacturing, C. Wang*, Z. Li*, J. Riemensberger*, G. Lihachev, M. Churaev, W. Kao, X. Ji, J. Zhang, T. Blesin, A. Davydova, Y. Chen, K. Huang, X. Wang, X. Ou, and T.J. Kippenberg, Nature 629, 784–790 (2024)
An ultra-broadband photonic-chip-based parametric amplifier, N. Kuznetsov*, A Nardi*, J. Riemensberger*, A. Davydova, M. Churaev, P. Seidler, T.J. Kippenberg, Nature 639, 928–934 (2025)
About the group
The group was founded in 2024 by Associate Professor Johann Riemensberger, holder of an NTNU Onsager Fellowship (2024–2030). Nefeli Dimogerontaki is a visiting scientist from the National Hellenistic Research Foundation (Prof. Odysseas Tsilipakos) and Trishala Mitra is a visiting scientist form the University of Aarhus (Prof. Nicolas Volet).
Members
Nefeli Dimogerontaki (Visiting Postdoc)
Andreas Jacobsen (PhD Student)
Trishala Mitra (Visiting Postdoc)
Mina Alexandra Thor (PhD Student)
Background of the group
Before NTNU, Johann was a postdoc in Tobias Kippenberg's Laboratory of Photonics and Quantum Measurements at EPFL from 2019 to 2024, as a Marie Skłodowska-Curie and SNSF Ambizione fellow. His work there helped establish silicon nitride and lithium tantalate as a platform for nonlinear integrated photonics and frequency combs. Highlights include massively parallel coherent LiDAR driven by soliton microcombs and a photonic-chip travelling-wave parametric amplifier with continuous-wave net gain.
Johann has obtained a PhD from the Technical University of Munich in the field of attosecond science generating and utilizing isolated attosecond pulses of light to investigate fundamental time limits of electron transport in atomic scale solid state materials.
Preprints:
Narrow-linewidth, piezoelectrically tunable photonic integrated blue laser, A. Siddharth, A.B. Gardner, X. Ji, S.U. Hulyal, M.S. Reichler, A. Attanasio, J. Riemensberger, S.A. Bhave, N. Volet, S. Bianconi, T.J. Kippenberg, arXiv preprint arXiv:2508.02568 (2025)
Publications:
Copper Damascene Process-Based High-Performance Thin Film Lithium Tantalate Modulators, M. Lin, Z. Li, A. Kotz, H. Larocque, J. Riemensberger, C. Koos, T.J. Kippenberg, Nature Communications (2026)
Monolithic piezoelectrically tunable hybrid integrated laser with sub-fiber laser coherence, A.S. Voloshin, A. Attanasio, A. Siddharth, S. Bianconi, A. Bancora, V. Shadymov, S. Leni, R.N. Wang, J. Riemensberger, S.A. Bhave, T.J. Kippenberg, Optica 12, 1442-1451 (2025)
320 GHz photonic-electronic analogue-to-digital converter (ADC) exploiting Kerr soliton microcombs, D. Fang, D. Drayss, H. Peng, G. Lihachev, C. Füllner, A. Kuzmin, P. Marin-Palomo, P. Matalla, P. Kathel, R.N. Wang, J. Riemensberger, M. Zhang, J. Witzens, J.C. Scheytt, W. Freude, S. Randel, T.J. Kippenberg, C. Koos, Light: Science & Applications, 14, 241-245 (2025)
Ultrafast tunable photonic integrated Pockels extended-DBR laser, A. Siddharth, S. Bianconi, R.N. Wang, Z. Qiu, A.S. Voloshin, M.J. Bereyhi, J. Riemensberger, T.J. Kippenberg, Nature Photonics 19, 709-717 (2025)
An ultra-broadband photonic-chip-based parametric amplifier, N. Kuznetsov*, A Nardi*, J. Riemensberger*, A. Davydova, M. Churaev, P. Seidler, T.J. Kippenberg, Nature 639, 928–934 (2025)
Ultrabroadband integrated electro-optic frequency comb in lithium tantalate, J. Zhang*, C. Wang*, C. Denney*, J. Riemensberger*, G. Lihachev, J. Hu, W. Kao, T. Blésin, N. Kuznetsov, Z. Li, M. Churaev, X. Ou, G. Santamaria-Botello, T.J. Kippenberg, Nature 637, 1096-1103 (2025)
Fundamental charge noise in electro-optic photonic integrated circuits, J. Zhang, Z. Li, J. Riemensberger, G. Lihachev, G. Huang, T.J. Kippenberg, Nature Physics 21, 304–311 (2025)
Frequency agile photonic integrated external cavity laser, G. Lihachev, A. Bancora, V. Snigirev, H. Tian, J. Riemensberger, V. Shadymov, A. Siddarth, A. Attanasio, R.N. Wang, D. Asani, A. Voloshin, S. Bhave, T.J. Kippenberg, APL Photonics 9,12 (2024)
Efficient mass manufacturing of high-density, ultra-low-loss Si3N4 photonic integrated circuits, X. Ji, R. Ning Wang, Y. Liu, J Riemensberger, Z. Qiu, T.J. Kippenberg, Optica 11 (10), 1397-1407 (2024)
Lithium tantalate photonic integrated circuits for volume manufacturing, C. Wang*, Z. Li*, J. Riemensberger*, G. Lihachev, M. Churaev, W. Kao, X. Ji, J. Zhang, T. Blesin, A. Davydova, Y. Chen, K.Huang, X. Wang, X. Ou, and T.J. Kippenberg, Nature 629, 784–790 (2024)
Integrated chirped photonic-crystal cavities in gallium phosphide for broadband soliton generation, A. Nardi, A. Davydova, N. Kuznetsov, M.H. Anderson, C. Möhl, J. Riemensberger, T.J. Kippenberg, P. Seidler, Optica 11 (10), 1454-1461 (2024)
Piezoelectrically tunable, narrow linewidth photonic integrated extended-DBR lasers, A. Siddharth, A. Attanasio, S. Bianconi, G. Lihachev, J. Zhang, Z. Qiu, G. Lihachev, J. Zhang, Z. Qiu, A. Bancora, S. Kenning, R.N. Wang, A.S. Voloshin, S.A. Bhave, J. Riemensberger, T.J. Kippenberg, Optica 11 (8), 1062-1069
Attosecond chronoscopy of the photoemission near a bandgap of a single-element layered dielectric, D. Potamianos, M. Schnitzenbaumer, C. Lemell, P. Scigalla, F. Libisch, E. Schock-Schmidtke, M. Haimerl, C. Schröder, M. Schäffer, J.T. Küchle, J. Riemensberger, K. Eberle, Y. Cui, U. Kleineberg, J. Burgdörfer, J.V. Barth, P. Feulner, F. Allegretti, R. Kienberger, Science Advances 10 (26) (2024)
A fully hybrid integrated Erbium-based laser, Y. Liu, Z. Qiu, X. Ji, A. Bancora, G. Lihachev, J. Riemensberger, R.N. Wang, A. Voloshin, T.J. Kippenberg, Nature Photonics, 1-7 (2024)
Voltage-tunable optical parametric oscillator with an alternating dispersion dimer integrated on a chip, D. Pidgaiko, A. Tusnin, J. Riemensberger, A. Stroganov, A. Tikan, T.J. Kippenberg, Optica 10,11 1582-1586 (2023)
Chaotic microcomb inertia-free parallel ranging, A. Lukashchuk, J. Riemensberger, A. Stroganov, G. Navickaite, T. J. Kippenberg, APL Photonics 8, 056102 (2023)
Ultrafast tunable lasers using lithium niobate integrated photonics, V. Snigirev, A. Riedhauser, G. Lihachev, J. Riemensberger, R.N. Wang, C. Möhl, M. Churaev, A. Siddharth, G. Huang, Y. Popoff, U. Drechsler, D. Caimi, S. Hönl, J. Liu, P. Seidler, T.J. Kippenberg, Nature 615, 411–417 (2023)
Chaotic microcomb-based parallel ranging, A. Lukashchuk, J. Riemensberger, A. Tusnin, J. Liu, T.J. Kippenberg, Nature Photonics 17*,*814–821 (2023)
Dissipative solitons and switching waves in dispersion folded Kerr cavities, M.H. Anderson, A. Tikan, A. Tusnin, J. Riemensberger, R.N. Wang, T.J. Kippenberg, Physical Review X 13,011040 (2023)
A heterogeneously integrated lithium niobate-on-silicon nitride photonic platform, M. Churaev, A. Riedhauser, R.N. Wang, C. Möhl, T. Blésin, M.A. Anderson, V. Snigirev, A. Siddharth, Y. Popoff, D. Caimi, S. Hönl, J. Riemensberger, J. Liu, P. Seidler, T.J. Kippenberg, Nature Communications, 14*,*3499 (2023)
High-density lithium niobate photonic integrated circuits, Z. Li, R.N. Wang, G. Lihachev, Z. Tan, V. Snigirev, M. Churaev, N. Kuznetsov, A. Siddharth, M.J. Bereyhi, J. Riemensberger, T.J. Kippenberg Nature Communications 14,4856 (2023)
A photonic integrated continuous-travelling-wave parametric amplifier, J. Riemensberger, N. Kusnetzov, J. Liu, J. He, R.N. Wang, T.J. Kippenberg, Nature 612, 56–61 (2022),
Low-noise frequency-agile photonic integrated lasers for coherent ranging, G. Lihachev*, J. Riemensberger*, W. Weng*, J. Liu, H. Tian, A. Siddharth, V. Snigirev, R.N. Wang, J. He, S.A. Bhave, T.J. Kippenberg, Nature Communications 13, 1 (2022)
Dual chirped microcomb-based parallel ranging at megapixel-line rates, A. Lukashchuk, J. Riemensberger, M. Karpov, J. Liu, T.J. Kippenberg, Nature Communications 13, 1 (2022)
Near ultraviolet photonic integrated lasers based on silicon nitride, A. Siddharth, T. Wunderer, G. Lihachev, A.S. Voloshin, C. Haller, R.N. Wang, M. Teepe, Z. Yang, J. Liu, J. Riemensberger, N. Grandjean, N. Johnson, T.J. Kippenberg APL Photonics 7, 4 (2022)
A photonic integrated circuit–based erbium-doped amplifier, Y. Liu*, Z. Qiu*, X. Yi, A. Lukashchuk, J. Riemensberger, M. Hafermann, R. N. Wang, C. Ronning, T.J. Kippenberg, Science 376, 6599 (2022)
Protected generation of dissipative Kerr solitons in supermodes of coupled optical microresonators, A. Tikan, A. Tusnin, J. Riemensberger, M. Churaev, X. Ji, K.N. Komagata, R.N. Wang, J. Liu, T.J. Kippenberg, Science Advances 8, 13 (2022)
Compact, spatial-mode-interaction-free, ultralow-loss, nonlinear photonic integrated circuits, X. Ji, J. Liu, J. He, R.N. Wang, Z. Qiu, J. Riemensberger, T.J. Kippenberg, Communications Physics 8, 13 (2022)
Dissipative Kerr solitons in a photonic dimer on both sides of the exceptional point, K. Komagata, A. Tusnin, J. Riemensberger, M. Churaev, H. Guo, A. Tikan, T. J. Kippenberg, Communications Physics 4, 159 (2021)
Laser soliton microcombs heterogeneously integrated on silicon, C. Xiang, J. Liu, J. Guo, L. Chang, R. N. Wang, W. Weng, J. Peters, W. Xie, Z. Zhang, J. Riemensberger, J. Selvidge, T.J. Kippenberg, J.E. Bowers, Science 373, 99-103 (2021)
Soliton microcomb based spectral domain optical coherence tomography, P. Marchand, J.C. Skehan, J. Riemensberger, J.-J. Ho, M.H.W. Pfeiffer, J. Liu, C. Hauger, T. Lasser, T.J. Kippenberg, Nature Communications 12, 427 (2021)
Emergent Nonlinear Phenomena in a Driven Dissipative Photonic Dimer, A. Tikan, J. Riemensberger, K. Komagata, S. Hönl, M. Churaev, C. Skehan, H. Guo, R. N. Wang, J. Liu, P. Seidler, T. J. Kippenberg, Nature Physics 17,604-610 (2021)
Massively parallel coherent laser ranging using a soliton microcomb, J. Riemensberger, A. Lukashchuk, M. Karpov, W. Weng, E. Lucas, J. Liu, T.J. Kippenberg, Nature 581, 164-170 (2020)
Photonic microwave generation in the X- and K-band using integrated soliton microcombs, J. Liu , E. Lucas, A. Raja, J. He, J. Riemensberger, R.N. Wang, M. Karpov, H. Guo, R. Bouchand, T.J. Kippenberg, Nature Photonics 8 468-491 (2020)
Understanding laser desorption with circularly polarized light, F. Ristow, J. Scheffel, X. Xu, N. Fehn, K. E. Oberhofer, J. Riemensberger, F. Mortaheb, R. Kienberger, U. Heiz, A. Kartouzian, H. Iglev, Chirality 32, 12, pp. 1341-1353 (2020)
Attosecond Dynamics of sp-Band Photoexcitation, J. Riemensberger, S. Neppl, D. Potamianos, M. Schäffer, M. Schnitzenbaumer, M. Ossiander, A. Guggenmos, U. Kleineberg, P. M. Echenique, F. Allegretti, D. Menzel, J. Barth, A. G. Borisov, A. K. Kazansky, R. Kienberger, and P. Feulner, Phys. Rev. Lett. 123, 176801 (2019)
Enantiospecific Desorption Triggered by Circularly Polarized Light, F. Mohateb, K. Oberhofer, J. Riemensberger, F. Ristow, R. Kienberger, U. Heiz, H. Iglev, A. Kartouzian*, Angewandte Chemie* 58, 44 15685-15689 (2019)
Few-Femtosecond Wave Packet Revivals in Ozone, T. Latka, V. Shirvanyan, M. Ossiander, O. Razskazovskaya, A. Guggenmos, M. Jobst, M. Fieß, S. Holzner, A. Sommer, M. Schultze, C. Jakubeit, J. Riemensberger, B. Bernhardt, W. Helml, F. Gatti, B. Lasorne, D. Lauvergnat, P. Decleva, G. J. Halász, Á. Vibók, and R. Kienberger, Phys. Rev. A 99, 063405 (2019)
Absolute Timing of the Photoelectric Effect, M. Ossiander*, J. Riemensberger*, S. Neppl, M. Mittermair, M. Schäffer, A. Duensing, M. S. Wagner, R. Heider, M.Wurzer, M. Gerl, M. Schnitzenbaumer, J.V. Barth, F. Libisch, C. Lemell, J. Burgdörfer, P. Feulner, R. Kienberger, Nature 561, 374-378 (2018)
Ultrafast quantum control of ionization dynamics in krypton, K. Hütten, M. Mittermair, S. O. Stock, R. Beerwerth, V. Shirvanyan, J. Riemensberger, A. Duensing, R. Heider, M. S. Wagner, A. Guggenmos, S. Fritzsche, N.M. Kabachnik, R. Kienberger, and B. Bernhardt, Nature Communications 9, 719 (2017)
Chromium/scandium multilayer mirrors for isolated attosecond pulses at 145 eV, A. Guggenmos, M. Jobst, M. Ossiander, S. Radünz, J. Riemensberger, M. Schäffer, A. Akil, C. Jakubeit, P. Böhm, S. Noever, B. Nickel, R. Kienberger, and U. Kleineberg, Optics Letters 40, 12, pp. 2846 (2015)
Universal formation dynamics and noise of Kerr-frequency combs in microresonators, T. Herr, J. Riemensberger, C. Wang, K. Hartinger, E. Gavartin, R. Holzwarth, M. L. Gorodetsky, T. J. Kippenberg, Nature Photonics 6, 480-487 (2012)
Dispersion engineered high-Q silicon Nitride Ring-Resonators via Atomic Layer Deposition, J. Riemensberger, K. Hartinger, T. Herr, V. Brasch, R. Holzwarth, T.J. Kippenberg, Optics Express 20, 25, pp. 27661-27669 (2012)
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Ny laser kan gi bedre selvkjørende biler og internett, Steinar Brandslet, Gemini, 14.7.2025