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arXiv · 2111.10292

Ultrahigh-$Q$ on-chip silicon-germanium microresonators

Ryan Schilling·Chi Xiong·Swetha Kamlapurkar·Abram Falk·Nathan Marchack·Stephen Bedell·Richard Haight·Christopher Scerbo·Hanhee Paik·Jason S. Orcutt
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Abstract

We demonstrate fully crystalline, single-mode ultrahigh quality factor integrated microresonators comprising epitaxially grown Si$_{0.86}$Ge$_{0.14}$ waveguide cores with silicon claddings. These waveguides support resonances with internal $Q >10^8$ for both polarization modes, a nearly order-of-magnitude improvement over that seen in prior integrated Si photonics platforms. The maximum $Q$ is $1.71\pm0.06 \times 10^8$ for the transverse magnetic (TM) polarization mode, corresponding to a loss of $0.39\pm0.02$ dB/m. Together with silicon's strong Kerr nonlinearity and low losses in the optical, microwave and acoustic regimes, our results could lead to the Si$_{1-x}$Ge$_x$/Si architecture unlocking important new avenues for Kerr frequency combs, optomechanics, and quantum transduction.

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Ryan Schilling, Chi Xiong, Swetha Kamlapurkar, Abram Falk, Nathan Marchack, Stephen Bedell, Richard Haight, Christopher Scerbo, Hanhee Paik, Jason S. Orcutt. 2021-11-19. Ultrahigh-$Q$ on-chip silicon-germanium microresonators. https://arxiv.org/abs/2111.10292

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