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arXiv · 2309.00936

Fabrication of low-loss III-V Bragg-reflection waveguides for parametric down-conversion

Hannah Thiel·Marita Wagner·Bianca Nardi·Alexander Schlager·Robert J. Chapman·Stefan Frick·Holger Suchomel·Martin Kamp·Sven Höfling·Christian Schneider·Gregor Weihs
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Abstract

Entangled photon pairs are an important resource for quantum cryptography schemes that go beyond point-to-point communication. Semiconductor Bragg-reflection waveguides are a promising photon-pair source due to mature fabrication, integrability, large transparency window in the telecom wavelength range, integration capabilities for electro-optical devices as well as a high second-order nonlinear coefficient. To increase performance we improved the fabrication of Bragg-reflection waveguides by employing fixed-beam-moving-stage optical lithography, low pressure and low chlorine concentration etching, and resist reflow. The reduction in sidewall roughness yields a low optical loss coefficient for telecom wavelength light of alpha_reflow = 0.08(6)mm^(-1). Owing to the decreased losses, we achieved a photon pair production rate of 8800(300)(mW*s*mm)^(-1) which is 15-fold higher than in previous samples.

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Hannah Thiel, Marita Wagner, Bianca Nardi, Alexander Schlager, Robert J. Chapman, Stefan Frick, Holger Suchomel, Martin Kamp, Sven Höfling, Christian Schneider, Gregor Weihs. 2023-09-02. Fabrication of low-loss III-V Bragg-reflection waveguides for parametric down-conversion. https://arxiv.org/abs/2309.00936

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