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arXiv · 2003.12176

Efficient photo-induced second harmonic generation in silicon photonics

Xiyuan Lu·Gregory Moille·Ashutosh Rao·Daron Westly·Kartik Srinivasan
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Abstract

Silicon photonics lacks a second-order nonlinear optical response in general because the typical constituent materials are centro-symmetric and lack inversion symmetry, which prohibits second-order nonlinear processes such as second harmonic generation (SHG). Here, for the first time, we realize efficient SHG in a silicon-based optical microresonator by combining a strong photo-induced effective second-order nonlinearity with resonant enhancement and perfect-phase matching. We show a record-high conversion efficiency of 2,500 %/W, which is 2 to 4 orders of magnitude larger than previous works. In particular, our devices realize mW-level SHG output powers with > 20 % power conversion efficiency. This demonstration is a major breakthrough in realizing efficient second-order nonlinear processes in silicon photonics, and paves the way for integrated self-referencing of Kerr frequency combs for compact optical frequency synthesis and optical clock technologies.

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Xiyuan Lu, Gregory Moille, Ashutosh Rao, Daron Westly, Kartik Srinivasan. 2020-03-26. Efficient photo-induced second harmonic generation in silicon photonics. https://doi.org/10.1038/s41566-020-00708-4

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