arXiv subjects

Patrice Féron

Publications and source records attributed to Patrice Féron.

7 recordsLinked to original sources

arXiv2022

High-Q Whispering-Gallery-Modes Microresonators in the Near-Ultraviolet Spectral Range

High-$Q$ whispering gallery mode microresonators are cornerstones to develop compact coherent sources like single frequency lasers or frequency combs. This work reports a detailed characterization of a whispering gallery mode microsphere in the near ultraviolet. Light coupling in the resonator is obtain thanks to a robust angle-polished fiber allowing to investigate the different coupling regimes. An intrinsic $Q_0$-factor of $2.2 \times 10^8$ and a finesse of $7.3 \times 10^4$ are reported at a wavelength of 420 nm. Physical mechanisms contributing to the $Q_0$-factor are discussed and routes to improve the performances are drawn. Such high-$Q$ factor and high finesse are key ingredients to ease the study of photonic devices based on WGM microresonators.

physics.optics↗

arXiv2019

Dynamical analysis of modal coupling in rare-earth whispering gallery mode micro-lasers

We report on an experimental study of laser regime in erbium-doped whispering gallery mode (WGM) microspheres under modal-coupling between the co- and counter-propagating modes. The evidence of modal coupling has been observed in the relative intensity noise spectrum of several WGM lasers. Cross-correlation measurements have been carried out in order to determine precisely the emission regimes. It is shown that depending on the material constituting the WGM resonator, frequency locked bidirectional emission or self-modulated regime can be reached. The control of the laser emission regime of WGM micro-lasers is of great importance in the aim of applications in microwave optics or optical sensor miniaturization.

physics.optics↗

arXiv2018

Microwave generation on an optical carrier in micro-resonator chains

We consider self-pulsing regimes in chains of Kerr nonlinear optical microresonators. By means of a supermodal diagonalization procedure of the conventional coupled-mode theory in time, we theoretically and numerically study the bifurcation diagrams of a singly pumped three-cavity and a doubly pumped four-cavity system: the latter allows us to predict thresholdless frequency tripling of a GHz modulation. These self-pulsing regimes are proven robust and will find applications in the generation and conversion of microwaves on an optical carrier.

physics.optics↗

arXiv2017

Theoretical and experimental analysis of rare earth whispering gallery mode laser relative intensity noise

The relative intensity noise (RIN) of a solid state whispering-gallery-mode class-B laser is studied both theoretically and experimentally under different pumping regimes. In particular, we show that harmonics of the spiking frequency are observed in the RIN spectrum. A rate equation model including Langevin forces and the nonlinear coupling between inverted ion and photon number fluctuations has been developed to reproduce the experimental results and to extract relevant physical parameters from the fitting of the RIN spectrum.

physics.optics↗

arXiv2016

Stable integrated hyper-parametric oscillator based on coupled optical microcavities

We propose a flexible scheme based on three coupled optical microcavities which permits to achieve stable oscillations in the microwave range, the frequency of which depends only on the cavity coupling rates. We find the different dynamical regimes (soft and hard excitation) to affect the oscillation intensity but not their period. This configuration may permit to implement compact hyper-parametric sources on an integrated optical circuit, with interesting applications in communications, sensing and metrology.

physics.optics↗

arXiv2014

Self-focused beams to couple light into a whispering-gallery mode resonator

We propose an original method to couple light into a whispering-gallery mode resonator. This method benefits from the mode selectivity and robustness of the prism-coupling along with the single-mode propagation of the fiber taper. It consists in a prism shaped crystal with a waveguide inscribed inside it. The waveguide is self-inscribed in-situ by beam self-trapping to allow an optimum coupling to a given resonator.

physics.optics↗

arXiv2007

Upconversion channels in Er3+:ZBLALiP: multicolour microspherical light source

We present results on the realization of an all-taper coupled, multicolour microspherical glass light source fabricated from the erbium doped fluoride glass ZBLALiP. Whispering gallery mode lasing and upconversion processes give rise to laser and fluorescent emissions at multiple wavelengths from the ultraviolet to the infrared. A single-mode tapered fibre coupling scheme, which serves to both launch pump light at 980 nm into the microresonator cavity and collect the resulting infrared lasing, is employed. We demonstrate the use of a second separate fibre taper to outcouple the upconversion spectrum over several hundred nanometers. Thirteen discrete emissions ranging from 320 to 850 nm have been observed in the upconversion spectrum. The absorption and fluorescence properties are studied and the processes responsible for the generation of the observed wavelengths are outlined.

physics.optics↗