# Juerg Leuthold
**Juerg Leuthold** (Jürg Leuthold) heads the Institute of Electromagnetic Fields (IEF) at [ETH Zurich](https://www.edgepedia.org/eth-zurich), where he has been Full Professor since 2013 and heads the Department of Information Science and Electrical Engineering (D-ITET).[1](https://ief.ee.ethz.ch/people/leuthold.html) • [2](https://micronarc-alpine-meeting.ch/wp/wp-content/uploads/2024/04/Leuthold_bio.pdf) His research focuses on photonics, plasmonics, and terahertz technologies, with emphasis on applications in communications and sensing, and he is known for [plasmonic modulators](https://www.edgepedia.org/plasmonic-modulator) and switches with record bandwidths, ultrafast graphene photodetectors, and nanoscale optical switches.[1](https://ief.ee.ethz.ch/people/leuthold.html) • [3](https://www.optica.org/get_involved/awards_and_honors/awards/award_winner_press_releases-2a8be47a26a5ec81e9523c90ea425bbc/2025_joseph_fraunhofer_award_robert_m_burley_prize_winner/)
| Key fact | Detail |
|---|---|
| Current position | Head of the Institute of Electromagnetic Fields (IEF) and of D-ITET, ETH Zurich; Full Professor since 2013[1](https://ief.ee.ethz.ch/people/leuthold.html) • [2](https://micronarc-alpine-meeting.ch/wp/wp-content/uploads/2024/04/Leuthold_bio.pdf) |
| Doctorate | PhD in physics, ETH Zurich, 1998, in integrated optics and all-optical communications[4](https://doi.org/10.3929/ethz-a-002052325) |
| Industry years | Bell Labs, Lucent Technologies, Holmdel, USA, 1999–2004[5](https://www.ipq.kit.edu/Staff_Leuthold.php) |
| Karlsruhe years | Full professor at KIT from July 2004; headed IPQ and IMT until returning to ETH in 2013[5](https://www.ipq.kit.edu/Staff_Leuthold.php) • [6](https://doron-prize.ch/laureat/professor-juerg-leuthold/) |
| Signature work | "Low-loss plasmon-assisted electro-optic modulator", Nature, 2018[7](https://pmc.ncbi.nlm.nih.gov/articles/PMC5935232/) |
| Record bandwidths | Plasmonic modulators at 1 THz; graphene-plasmonic detectors above 500 GHz[3](https://www.optica.org/get_involved/awards_and_honors/awards/award_winner_press_releases-2a8be47a26a5ec81e9523c90ea425bbc/2025_joseph_fraunhofer_award_robert_m_burley_prize_winner/) |
| Honors | Optica Fellow (2009), IEEE Fellow, 2025 Joseph Fraunhofer Award/Robert M. Burley Prize[8](https://www.optica.org/History/Biographies/bios/Juerg_Leuthold) |
## Education and early career
Leuthold studied physics at ETH Zurich between 1986 and 1991.[6](https://doron-prize.ch/laureat/professor-juerg-leuthold/) According to the ETH Zurich dissertation record, his doctoral thesis, completed in 1998 at ETH Zurich's Institute of Quantum Electronics, was titled *Advanced indium-phosphide waveguide Mach-Zehnder interferometer all-optical switches and wavelength converters*; it introduced all-optical devices built on a Mach-Zehnder interferometer with semiconductor optical amplifiers on the interferometer arms, usable for switching, multiplexing, demultiplexing, and wavelength conversion in high-speed time-division telecommunication.[4](https://doi.org/10.3929/ethz-a-002052325) • [6](https://doron-prize.ch/laureat/professor-juerg-leuthold/)
From 1999 to 2004 he worked at [Bell Labs](https://www.edgepedia.org/bell-labs), Lucent Technologies in Holmdel, USA, performing device and system research with III–V semiconductor and silicon optical bench materials for high-speed telecommunications.[5](https://www.ipq.kit.edu/Staff_Leuthold.php)
## Career record
In July 2004 Leuthold became a full professor at the [Karlsruhe Institute of Technology](https://www.edgepedia.org/karlsruhe-institute-of-technology) (KIT), where he headed the Institute of Photonics and Quantum Electronics (IPQ) and directed the Helmholtz Research Association Institute of Microstructure Technology (IMT).[5](https://www.ipq.kit.edu/Staff_Leuthold.php) His Karlsruhe research areas included terahertz technology and teratronics, plasmonics and nanophotonics, nonlinear optics, integrated optics in silicon and InP, and high-speed optical communications.[5](https://www.ipq.kit.edu/Staff_Leuthold.php) He returned to Switzerland in 2013 upon appointment as Head of the Institute of Electromagnetic Fields at ETH Zurich.[6](https://doron-prize.ch/laureat/professor-juerg-leuthold/) As of 2024 he also heads the Department of Information Science and Electrical Engineering (D-ITET).[2](https://micronarc-alpine-meeting.ch/wp/wp-content/uploads/2024/04/Leuthold_bio.pdf)
## Representative work
The 2018 Nature paper "Low-loss plasmon-assisted electro-optic modulator" (volume 556, pages 483–486) demonstrated a plasmonic electro-optic ring modulator based on resonant switching: light couples to the lossy surface plasmon polaritons only in the device's off state, when it is in resonance, so the metal's ohmic losses are bypassed in the on state.[7](https://pmc.ncbi.nlm.nih.gov/articles/PMC5935232/) A single device combined low on-chip optical losses of 2.5 dB, high-speed operation above 100 GHz, energy efficiency of 12 fJ/bit, low thermal drift (4‰ K⁻¹), and a compact footprint with a sub-wavelength radius of 1 µm.[7](https://pmc.ncbi.nlm.nih.gov/articles/PMC5935232/)
## Nanomechanical switches and graphene detection
Two further Science papers define the group's record. The 2019 paper "Nano–opto-electro-mechanical switches operated at CMOS-level voltages" (15 November 2019, volume 366, pages 860–864) demonstrated hybrid photonic-plasmonic switches that fully switch light at CMOS-level voltages of about 1.4 V with 0.1 dB optical losses and a footprint of about 10 µm².[9](https://pmc.ncbi.nlm.nih.gov/articles/PMC11641242/) Actuation relies on a 40 nm thin gold membrane of low mass, enabling nanosecond-scale switching; resonant operation with quality factors above 3000 makes on-off switching with 200 mV feasible.[9](https://pmc.ncbi.nlm.nih.gov/articles/PMC11641242/) The switch's central feature is a gold membrane only 40 nanometers thick and a few micrometers wide, separated from a silicon substrate by an aluminum oxide disk; it can be toggled several million times per second with little more than one volt, removing the need for bulky power-hungry amplifiers.[10](https://ethz.ch/en/news-and-events/eth-news/news/2019/11/a-super-fast-light-switch-for-future-cars-and-computers.html) The work was carried out with the [National Institute of Standards and Technology](https://www.edgepedia.org/national-institute-of-standards-and-technology) (USA) and Chalmers University (Sweden).[10](https://ethz.ch/en/news-and-events/eth-news/news/2019/11/a-super-fast-light-switch-for-future-cars-and-computers.html)
The 2023 Science paper "Metamaterial graphene photodetector with bandwidth exceeding 500 gigahertz" (15 June 2023, volume 380, pages 1169–1174) demonstrated a graphene photodetector with a flat-frequency response above 500 GHz, operating under ambient conditions across a 200-nanometer-wide spectral band with center wavelengths adaptable from below 1400 to above 4200 nanometers.[11](https://doi.org/10.1126/science.adg8017) • [12](https://europepmc.org/article/med/37319195) The detector combines graphene with metamaterial perfect absorbers illuminated directly from a single-mode fiber, breaking with the conventional miniaturization of photodetectors on an integrated photonic platform and allowing much higher optical powers.[11](https://doi.org/10.1126/science.adg8017) Graphene's low absorption was counteracted by co-integrating it in the metamaterial structure; the IEF group described the result as the fastest photodetector at the time, beating previous record demonstrations by a factor of four.[13](https://ief.ee.ethz.ch/news-and-events/electromagnetic-fields--ief--news/2023/06/metamaterial-graphene-photodetector-with-500-ghz-bandwidth.html) An earlier Science paper, "High-speed plasmonic modulator in a single metal layer", presented an all-plasmonic 116-gigabit-per-second electro-optical modulator in which grating couplers, splitters, polarization rotators, and the active phase-shifter section all sit in a single metal layer.[14](https://www.science.org/doi/10.1126/science.aan5953)
## Comparison with other modulator technologies
Plasmonic modulators introduced over the four years before 2019 reached ultracompact footprints of tens of µm², ultralow energy consumption of 2.8 fJ/bit at 100 GBd, and flat frequency responses up to 170 GHz and 325 GHz.[15](https://publica-rest.fraunhofer.de/server/api/core/bitstreams/b0d5bbf0-ea29-406e-b5ec-129f338e7fe2/content) A 2019 APL Photonics paper from IEF with Fraunhofer IAF pushed this to plasmonic Mach-Zehnder modulators with a flat response up to 500 GHz, device lengths below 25 µm, and high linearity, with a third-order input intercept point of 18.9 dBm.[15](https://publica-rest.fraunhofer.de/server/api/core/bitstreams/b0d5bbf0-ea29-406e-b5ec-129f338e7fe2/content) For comparison, an integrated lithium niobate-on-insulator Mach-Zehnder modulator achieved a 3-dB bandwidth of about 30 GHz at a length of the order of 20 mm, with roughly 0.4 dB device loss and a half-wave voltage of about 1 V: an order of magnitude longer device and a far lower bandwidth.[15](https://publica-rest.fraunhofer.de/server/api/core/bitstreams/b0d5bbf0-ea29-406e-b5ec-129f338e7fe2/content)
## Honors and recognition
Leuthold became an Optica Fellow in 2009 and is also a Fellow of IEEE.[8](https://www.optica.org/History/Biographies/bios/Juerg_Leuthold) He is a member of the Swiss Academy of Engineering Sciences (SATW) and, according to his ETH page, a corresponding member of the Heidelberg Academy of Sciences; the Optica biography lists him as a member.[1](https://ief.ee.ethz.ch/people/leuthold.html) • [8](https://www.optica.org/History/Biographies/bios/Juerg_Leuthold) His work has been awarded an Advanced Grant of the [European Research Council](https://www.edgepedia.org/european-research-council), the State Research Award of Baden-Württemberg, and the doron Prize, and he served on the Board of Directors of the Optical Society of America until 2018.[16](https://hector-fellow-academy.de/en/research/hector-fellows/juerg-leuthold/) In 2025 Optica selected him for the Joseph Fraunhofer Award/Robert M. Burley Prize for pioneering plasmonics-based devices, in particular broadband modulators and detectors with the highest bandwidths.[3](https://www.optica.org/get_involved/awards_and_honors/awards/award_winner_press_releases-2a8be47a26a5ec81e9523c90ea425bbc/2025_joseph_fraunhofer_award_robert_m_burley_prize_winner/)
## Recent work
The group's latest plasmonic modulators feature a bandwidth of 1 THz, and its graphene-plasmonic detectors offer bandwidths in excess of 500 GHz.[3](https://www.optica.org/get_involved/awards_and_honors/awards/award_winner_press_releases-2a8be47a26a5ec81e9523c90ea425bbc/2025_joseph_fraunhofer_award_robert_m_burley_prize_winner/) The group has also pioneered some of the first optical memristive devices, operating with as little as a single atom, and has mimicked a Tbit/s line-rate satellite feeder link in a field trial from the top of a Swiss mountain to a city.[3](https://www.optica.org/get_involved/awards_and_honors/awards/award_winner_press_releases-2a8be47a26a5ec81e9523c90ea425bbc/2025_joseph_fraunhofer_award_robert_m_burley_prize_winner/) At OFC 2026 in March 2026, the group demonstrated the first silicon-photonics plasmonic O-band resonant ring modulator, with on-chip losses of 2.2 dB, reaching net 400 Gbps with PAM8 signaling and improved temperature stability compared with pure silicon-photonic rings.[17](https://opg.optica.org/abstract.cfm?uri=OFC-2026-M2B.5) In a September 2025 SPIE abstract, Leuthold noted that plasmonics had been touted as a solution for highest speed for the past 40 years, yet practical solutions with bandwidths in excess of 500 GHz have only recently been introduced.[18](https://doi.org/10.1117/12.3067839)
## References
1. Leuthold, Juerg, Prof. Dr. – Institute of Electromagnetic Fields (IEF), ETH Zurich. https://ief.ee.ethz.ch/people/leuthold.html
2. Prof. Dr. Juerg Leuthold (conference biography PDF, 2024). https://micronarc-alpine-meeting.ch/wp/wp-content/uploads/2024/04/Leuthold_bio.pdf
3. 2025 Joseph Fraunhofer Award/Robert M. Burley Prize Winner – Optica. https://www.optica.org/get_involved/awards_and_honors/awards/award_winner_press_releases-2a8be47a26a5ec81e9523c90ea425bbc/2025_joseph_fraunhofer_award_robert_m_burley_prize_winner/
4. Advanced indium-phosphide waveguide Mach-Zehnder interferometer all-optical switches and wavelength converters (ETH Zurich dissertation). https://doi.org/10.3929/ethz-a-002052325
5. Curriculum Vitae – Prof. Dr. Juerg Leuthold – KIT IPQ. https://www.ipq.kit.edu/Staff_Leuthold.php
6. Professor Jürg Leuthold – doron Prize. https://doron-prize.ch/laureat/professor-juerg-leuthold/
7. Low-loss plasmon-assisted electro-optic modulator (Nature, 2018) – author manuscript. https://pmc.ncbi.nlm.nih.gov/articles/PMC5935232/
8. Juerg Leuthold – Optica biography. https://www.optica.org/History/Biographies/bios/Juerg_Leuthold
9. Nano-opto-electro-mechanical Switches Operated at CMOS-level Voltages (Science, 2019) – author manuscript. https://pmc.ncbi.nlm.nih.gov/articles/PMC11641242/
10. A super-fast "light switch" for future cars and computers – ETH Zurich. https://ethz.ch/en/news-and-events/eth-news/news/2019/11/a-super-fast-light-switch-for-future-cars-and-computers.html
11. Metamaterial graphene photodetector with bandwidth exceeding 500 gigahertz (Science, 2023). https://doi.org/10.1126/science.adg8017
12. Metamaterial graphene photodetector with bandwidth exceeding 500 gigahertz – Europe PMC. https://europepmc.org/article/med/37319195
13. Science Publication: Graphene photodetector shows unprecedented speed – IEF, ETH Zurich. https://ief.ee.ethz.ch/news-and-events/electromagnetic-fields--ief--news/2023/06/metamaterial-graphene-photodetector-with-500-ghz-bandwidth.html
14. High-speed plasmonic modulator in a single metal layer (Science). https://www.science.org/doi/10.1126/science.aan5953
15. 500 GHz plasmonic Mach-Zehnder modulator enabling sub-THz microwave photonics (APL Photonics, 2019). https://publica-rest.fraunhofer.de/server/api/core/bitstreams/b0d5bbf0-ea29-406e-b5ec-129f338e7fe2/content
16. Prof. Dr. Jürg Leuthold – Hector Fellow Academy. https://hector-fellow-academy.de/en/research/hector-fellows/juerg-leuthold/
17. O-Band Silicon-Plasmonic Resonant Ring Modulator Demonstrating Net-Rates of 400 Gbps (OFC 2026). https://opg.optica.org/abstract.cfm?uri=OFC-2026-M2B.5
18. Plasmonics: a solution for highest speed (SPIE, 2025). https://doi.org/10.1117/12.3067839
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*Topic: Encyclopedia › Physical world and mathematics › Physical and mathematical scientists › Physicists and astronomers › Researchers in applied physics, optics, photonics, and plasma physics › Optical communications and integrated photonics*
*Initially written Sep 21, 2026 · Reviewed: Sep 25, 2026 · Edited: Sep 25, 2026; Oct 21, 2026 · Last review: Sep 25, 2026*
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