Publications by Michael Wolfgang Geiselmann

Enhancing Microcomb Efficiency via Pump Recycling in a Chip-Integrated Gain Medium

Continuous-wave (CW) laser-driven integrated Kerr microresonators enable broadband optical frequency combs with high repetition rates and low threshold power, in a compact footprint. A drawback of such microcombs is the low conversion efficiency from the p ...

IEEE2025

Octave-Spanning Soliton Microcomb with Over 50% Conversion Efficiency Enabled by Strong Mode Coupling

Michael Wolfgang Geiselmann

Dissipative Kerr solitons (DKS), which provide coherent and stable frequency combs, have emerged as a powerful tool for a wide range of applications in metrology, spectroscopy, telecommunications [1]. However, one of the major challenges hindering their pr ...

IEEE2025

High-power, Thermally-accessible Dissipative Kerr Soliton Generation

Michael Wolfgang Geiselmann

Dissipative Kerr solitons offer low power consumption, flexible line spacing, and CMOS compatibility, making them ideal for diverse applications [1]. However, their adoption still faces substantial challenges: low soliton power, and thermo-optic instabilit ...

IEEE2025

Improving Limit-of-Detection in High-Sensitivity Plasmo-Photonic Mach-Zehnder interferometer refractive index sensors

Michael Wolfgang Geiselmann

This work presents a dual plasmo-photonic branch Mach-Zehnder interferometer refractive index sensor integrated on a Si3N4 platform, with both the sensor and reference arms hosting identical aluminum plasmonic metal stripes. Experimental evaluation of the ...

Institute of Electrical and Electronics Engineers (IEEE)2025

Sub-2W tunable laser based on silicon photonics power amplifier

Michael Wolfgang Geiselmann

High-power tunable lasers are intensely pursued due to their vast application potential such as in telecom, ranging, and molecular sensing. Integrated photonics, however, is usually considered not suitable for high-power applications mainly due to its smal ...

Springer Science and Business Media LLC2025

O-Band Gaas Quantum Dot Optical Amplifier Integrated on an Advanced Sin Platform

Michael Wolfgang Geiselmann

We present an O-band GaAs optical amplifier integrated on an advanced SiN platform using micro-transfer printing. A polycrystalline Si layer facilitates light coupling between GaAs and SiN, resulting 5 dB on-chip gain at 1300 nm. ...

IEEE2025

Up to 50 dB Extinction in Broadband Single-Stage Thermo-Optic Mach-Zehnder Interferometers for Programmable Low-Loss Silicon Nitride Photonic Circuits

Michail Zervas, Michael Wolfgang Geiselmann

We demonstrate single-stage thermo-optic Si3N4 interferometers with (46.1 +/- 2.5) dB average extinction ratio over 1460-1640 nm (approximate to 50x of typical devices). We analyze performance requirements for creating reconfigurable high-quality-factor re ...

IEEE2021

Towards integrated photonic interposers for processing octave-spanning microresonator frequency combs

Michail Zervas, Davide Sacchetto, Michael Wolfgang Geiselmann

Microcombs-optical frequency combs generated in microresonators-have advanced tremendously in the past decade, and are advantageous for applications in frequency metrology, navigation, spectroscopy, telecommunications, and microwave photonics. Crucially, m ...

SPRINGERNATURE2021

Integrated Photonic Interposers for Processing Octave-Spanning Microresonator Frequency Combs

Michail Zervas, Davide Sacchetto, Michael Wolfgang Geiselmann

We demonstrate multiple silicon-nitride nanophotonic elements for on-chip processing of octave-spanning microresonator frequency combs. Dichroic filters, multimode interferometers, and tunable add-drop microring filters are shown along with soliton microco ...

IEEE2020

A microphotonic astrocomb

Stefan Kundermann, Tobias Kippenberg, Tobias Herr, Michael Wolfgang Geiselmann, Junqiu Liu, Miles Henry Anderson

Earth-like planets, dark energy and variability of fundamental physical constants can be discovered by observing wavelength shifts in the optical spectra of astronomical objects(1-5). These wavelength shifts are so tiny that exquisitely accurate and precis ...

Nature Publishing Group2019

Double inverse nanotapers for efficient light coupling to integrated photonic devices

Michail Zervas, Tobias Kippenberg, Martin Hubert Peter Pfeiffer, Michael Wolfgang Geiselmann, Hairun Guo, Junqiu Liu, Clemens Herkommer, Arslan Sajid Raja

2018

Photonic Damascene Process for Low-Loss, High-Confinement Silicon Nitride Waveguides

Michail Zervas, Tobias Kippenberg, Martin Hubert Peter Pfeiffer, Michael Wolfgang Geiselmann, Clemens Herkommer

2018

Self-referenced photonic chip soliton Kerr frequency comb

Tobias Kippenberg, Victor Brasch, Erwan Guillaume Albert Lucas, John David Jost, Michael Wolfgang Geiselmann

Self-referencing turns pulsed laser systems into self-referenced frequency combs. Such frequency combs allow counting of optical frequencies and have a wide range of applications. The required optical bandwidth to implement self-referencing is typically ob ...

2017

Coupling Ideality of Integrated Planar High-Q Microresonators

Tobias Kippenberg, Martin Hubert Peter Pfeiffer, Michael Wolfgang Geiselmann, Junqiu Liu

Chip-scale optical microresonators with integrated planar optical waveguides are useful building blocks for linear, nonlinear, and quantum-optical photonic devices alike. Loss reduction through improving fabrication processes results in several integrated ...

American Physical Society (APS)2017

Intermode Breather Solitons in Optical Microresonators

Tobias Kippenberg, Martin Hubert Peter Pfeiffer, Erwan Guillaume Albert Lucas, John David Jost, Michael Wolfgang Geiselmann, Maxim Karpov, Hairun Guo, Junqiu Liu, Miles Henry Anderson

Dissipative solitons can be found in a variety of systems resulting from the double balance between dispersion and nonlinearity, as well as gain and loss. Recently, they have been observed to spontaneously form in Kerr nonlinear microresonators driven by a ...

American Physical Society2017

Bringing short-lived dissipative Kerr soliton states in microresonators into a steady state

Tobias Kippenberg, Martin Hubert Peter Pfeiffer, Victor Brasch, Michael Wolfgang Geiselmann

Dissipative Kerr solitons have recently been generated in optical microresonators, enabling ultrashort optical pulses at microwave repetition rates, that constitute coherent and numerically predictable Kerr frequency combs. However, the seeding and excitat ...

Optical Society of America2016

Frequency-comb-assisted broadband precision spectroscopy with cascaded diode lasers

Tobias Kippenberg, Martin Hubert Peter Pfeiffer, Victor Brasch, Arne Kordts, Michael Wolfgang Geiselmann, Hairun Guo, Junqiu Liu

Frequency-comb-assisted diode laser spectroscopy, employing both the accuracy of an optical frequency comb and the broad wavelength tuning range of a tunable diode laser, has been widely used in many applications. In this Letter, we present a novel method ...

Optical Society of America2016

Self-Referenced, Chipscale Kerr Frequency Comb without External Broadening

Tobias Kippenberg, Victor Brasch, Erwan Guillaume Albert Lucas, John David Jost, Michael Wolfgang Geiselmann

A Kerr frequency comb generated in an integrated silicon nitride microresonator is self-referenced using the 2f-3f approach. With an intrinsic bandwidth of two-thirds of an octave no additional, external broadening of the spectrum is required. ...

Ieee2016

Raman Self-Frequency Shift of Dissipative Kerr Solitons in an Optical Microresonator

Michail Zervas, Tobias Kippenberg, Martin Hubert Peter Pfeiffer, Victor Brasch, Arne Kordts, Michael Wolfgang Geiselmann, Maxim Karpov, Hairun Guo

We experimentally observed the Raman-induced self-frequency shift of high-intensity dissipative Kerr solitons in high-Q silicon nitride microresonators. The Raman redshift is linearly dependent on the pump-frequency-detuning, associated with the tunability ...

Ieee2016

Raman Self-Frequency Shift of Dissipative Kerr Solitons in an Optical Microresonator

Michail Zervas, Tobias Kippenberg, Martin Hubert Peter Pfeiffer, Victor Brasch, Arne Kordts, Michael Wolfgang Geiselmann, Maxim Karpov, Hairun Guo

The formation of temporal dissipative Kerr solitons in microresonators driven by a continuous-wave laser enables the generation of coherent, broadband, and spectrally smooth optical frequency combs as well as femtosecond pulse sources with compact form fac ...

American Physical Society2016