Wang Mingkang, Perez-Morelo Diego J, Aksyuk Vladimir A
Opt Express. 2021 Mar 1;29(5):6967-6979. doi: 10.1364/OE.416576.
Key for optical microresonator engineering, the total intrinsic loss is easily determined by spectroscopy; however, quantitatively separating absorption and radiative losses is challenging, and there is not a general and robust method. Here, we propose and experimentally demonstrate a general all-optical characterization technique for separating the loss mechanisms with high confidence using only linear spectroscopic measurements and an optically measured resonator thermal time constant. We report the absorption, radiation, and coupling losses for ten whispering-gallery modes of three different radial orders on a Si microdisk. Although the total dissipation rates show order-of-magnitude differences, the small absorptive losses are successfully distinguished from the overwhelming radiation losses and show similar values for all the modes as expected for the bulk material absorption.
对于光学微谐振器工程而言，关键在于通过光谱学可轻松确定总本征损耗；然而，定量分离吸收损耗和辐射损耗具有挑战性，且不存在通用且可靠的方法。在此，我们提出并通过实验证明了一种通用的全光学表征技术，该技术仅使用线性光谱测量和光学测量的谐振器热时间常数就能高置信度地分离损耗机制。我们报告了硅微盘上三种不同径向阶数的十个回音壁模式的吸收、辐射和耦合损耗。尽管总耗散率显示出数量级差异，但小的吸收损耗已成功地与占主导的辐射损耗区分开来，并且对于所有模式而言，其值与体材料吸收预期的相似。
