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

Davide Sacchetto, Michail Zervas, 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

Davide Sacchetto, Michail Zervas, 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

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

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