arXiv subjects

Michael Geiselmann

Publications and source records attributed to Michael Geiselmann.

23 records · Page 2Linked to original sources

arXiv2015

Photonic chip based optical frequency comb using soliton induced Cherenkov radiation

By continuous wave pumping of a dispersion engineered, planar silicon nitride microresonator, continuously circulating, sub-30fs short temporal dissipative solitons are generated, that correspond to pulses of 6 optical cycles and constitute a coherent optical frequency comb in the spectral domain. Emission of soliton induced Cherenkov radiation caused by higher order dispersion broadens the spectral bandwidth to 2/3 of an octave, sufficient for self referencing, in excellent agreement with recent theoretical predictions and the broadest coherent microresonator frequency comb generated to date. In a further step, this frequency comb is fully phase stabilized. The ability to preserve coherence over a broad spectral bandwidth using soliton induced Cherenkov radiation marks a critical milestone in the development of planar optical frequency combs, enabling on one hand application in e.g. coherent communications, broadband dual comb spectroscopy and Raman spectral imaging, while on the other hand significantly relaxing dispersion requirements for broadband microresonator frequency combs and providing a path for their generation in the visible and UV. Our results underscore the utility and effectiveness of planar microresonator frequency comb technology, that offers the potential to make frequency metrology accessible beyond specialized laboratories.

physics.optics↗

arXiv2015

Raman induced soliton self-frequency shift in microresonator Kerr frequency combs

The formation of temporal dissipative solitons in continuous wave laser driven microresonators enables the generation of coherent, broadband and spectrally smooth optical frequency combs as well as femtosecond pulses with compact form factor. Here we report for the first time on the observation of a Raman-induced soliton self-frequency shift for a microresonator soliton. The Raman effect manifests itself in amorphous SiN microresonator based single soliton states by a spectrum that is hyperbolic secant in shape, but whose center is spectrally red-shifted (i.e. offset) from the continuous wave pump laser. The Raman induced spectral red-shift is found to be tunable via the pump laser detuning and grows linearly with peak power. The shift is theoretically described by the first order shock term of the material's Raman response, and we infer a Raman shock time of 20 fs for amorphous SiN. Moreover, we observe that the Raman induced frequency shift can lead to a cancellation or overcompensation of the soliton recoil caused by the formation of a (coherent) dispersive wave. The observations are in excellent agreement with numerical simulations based on the Lugiato-Lefever equation (LLE) with a Raman shock term. Our results contribute to the understanding of Kerr frequency combs in the soliton regime, enable to substantially improve the accuracy of modeling and are relevant to the fundamental timing jitter of microresonator solitons.

physics.optics↗

arXiv2015

Coupling of individual quantum emitters to channel plasmons

Efficient light-matter interaction lies at the heart of many emerging technologies that seek on-chip integration of solid-state photonic systems. Plasmonic waveguides, which guide the radiation in the form of strongly confined surface plasmon-polariton modes, represent a promising solution to manipulate single photons in coplanar architectures with unprecedented small footprints. Here we demonstrate coupling of the emission from a single quantum emitter to the channel plasmon polaritons supported by a V-groove plasmonic waveguide. Extensive theoretical simulations enable us to determine the position and orientation of the quantum emitter for optimum coupling. Concomitantly with these predictions, we demonstrate experimentally that 42% of a single nitrogen vacancy centre emission efficiently couples into the supported modes of the V-groove. This work paves the way towards practical realization of efficient and long distance transfer of energy for integrated solid-state quantum systems.

physics.optics↗

arXiv2014

Fast optical modulation of the fluorescence from a single NV centre

The much sought after optical transistor --the photonic counterpart of the electronic transistor-- is poised to become a central ingredient in the development of optical signal processing. The motivation for using photons rather than electrons not only comes from their faster dynamics but also from their lower crosstalk and minor environmental decoherence, which enable a high degree of integration and the realization of quantum operations. A single-molecule transistor has been recently demonstrated at cryogenic temperatures. Here, we demonstrate that a single NV centre at room temperature can operate as an optical switch under non-resonant CW illumination. We show optical modulation of more than 80% and time response faster than 100 ns in the green-laser-driven fluorescence signal, which we control through an independent near-infrared (NIR) gating laser. Our study indicates that the NIR laser triggers a fast-decay channel of the NV mediated by promotion of the excited state to a dark band. This simple concept opens a new approach towards the implementation of nanoscale optical switching devices.

physics.optics↗

arXiv2012

3D optical manipulation of a single electron spin

Nitrogen vacancy (NV) centers in diamond are promising elemental blocks for quantum optics [1, 2], spin-based quantum information processing [3, 4], and high-resolution sensing [5-13]. Yet, fully exploiting these capabilities of single NV centers requires strategies to accurately manipulate them. Here, we use optical tweezers as a tool to achieve deterministic trapping and 3D spatial manipulation of individual nano-diamonds hosting a single NV spin. Remarkably, we find the NV axis is nearly fixed inside the trap and can be controlled in-situ, by adjusting the polarization of the trapping light. By combining this unique spatial and angular control with coherent manipulation of the NV spin and fluorescent lifetime measurements near an integrated photonic system, we prove optically trapped NV center as a novel route for both 3D vectorial magnetometry and sensing of the local density of optical states.

physics.optics↗