Valérian Thiel

Nonlinear photon subtraction from a multimode quantum field

We consider theoretically how to extract mode-dependent single photons from a time and frequency multimode nonclassical beam. To achieve this task, we calculate the properties of sum frequency generation with a pulse shaped pump, taking into account both temporal and spatial degrees of freedom. We show that using a noncollinear configuration it is possible to achieve a mode-dependent weakly reflective beam splitter, with Schmidt number compatible with photon extraction for continuous variable regime tasks. We make explicit the possible application to the degaussification of highly multimode squeezed frequency combs.

Phase-amplitude noise correlations in an optical frequency comb

The use of optical frequency combs (FC) for high precision measurements is limited by fluctuations of the comb structure [1]. The FC fluctuations can be modelled as uncoupled noise modes associated with a few global parameters namely power, central wavelength, carrier-envelope offset (CEO) phase, repetition rate, dispersion [2, 3]. However, the correlations between phase and amplitude noises, which play an important role to determine the comb stability, have never been described in terms of these noise modes. In this study, we present a new scheme to measure both phase and amplitude noises simultaneously, and provide a modal description of their correlations to unveil the underlying physical mechanisms.

Quantum limited parameter estimation with pulse shaped frequency combs

Combining a multi-color homodyne detection scheme with techniques from quantum optics, we show the feasibility of shot-noise limited measurements of a mediums parameters, while also being able to compensate for their fluctuations.

Broadband Fabry-Perot cavity for quantum-limited frequency comb metrology

We study a broadband, high finesse optical cavity in combination with spectrally resolved balanced homodyne detection as a tool to analyze the modal structure of a 40nm FWHM optical frequency comb in amplitude and phase.