Publications by Joachim Armand Simonne Ciers

Smooth GaN membranes by polarization-assisted electrochemical etching

Nicolas Grandjean, Jean-François Carlin, Joachim Armand Simonne Ciers

III-nitride membranes offer promising perspectives and improved device designs in photonics, electronics, and optomechanics. However, the removal of the growth substrate often leads to a rough membrane surface, which increases scattering losses in optical ...

AMER INST PHYSICS2021

Ultrafast-nonlinear ultraviolet pulse modulation in an AlInGaN polariton waveguide operating up to room temperature

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Joachim Armand Simonne Ciers, Davide Maria Di Paola

Ultrafast nonlinear photonics enables a host of applications in advanced on-chip spectroscopy and information processing. These rely on a strong intensity dependent (nonlinear) refractive index capable of modulating optical pulses on sub-picosecond timesca ...

Nature Research2021

Polariton relaxation and polariton nonlinearities in nonresonantly cw-pumped III-nitride slab waveguides

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Joachim Armand Simonne Ciers, Gordon Jens Callsen

Polariton lasers are mostly based on planar cavities. Here we focus on an alternative configuration with slab waveguide modes strongly coupled to excitons confined in GaN/AlGaN quantum wells. We study experimentally and theoretically polariton relaxation a ...

2020

Carbon Footprint of Academic Air Travel: A Case Study in Switzerland

László Dániel Tóth, Guillaume Jean Op 't Veld, Joachim Armand Simonne Ciers, Aleksandra Mandic

Relatively low travel costs and abundant opportunities for research funding in Switzerland and other developed countries allow researchers large amounts of international travel and collaborations, leading to a substantial carbon footprint. Increasing willi ...

2019

Light-Matter Interaction in III-Nitride Waveguides: Propagating Polaritons and Optical Gain

Joachim Armand Simonne Ciers

III-nitride waveguides featuring AlInN claddings and GaN/AlGaN quantum wells (QWs) offer promising perspectives for applications in many fields of short-wavelength photonics. Thanks to their nearly lattice-matched nature, these structures exhibit an excell ...

EPFL2018

Propagating Polaritons in III-Nitride Slab Waveguides

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Gwénolé Jean Jacopin, Joachim Armand Simonne Ciers

We report on III-nitride waveguides with c-plane GaN/(Al,Ga)N quantum wells in the strong light-matter coupling regime supporting propagating polaritons. They feature a normal-mode splitting as large as 60 meV at low temperatures thanks to the large overla ...

American Physical Society (APS)2017