Compensation of thermal refraction effect in high-Q toroidal microresonator by polydimethylsiloxane coating

被引：117

作者：

He, L. ^{[1
]}

Xiao, Y-F. ^{[1
]}

Dong, C. ^{[1
]}

Zhu, J. ^{[1
]}

Gaddam, V. ^{[1
]}

Yang, L. ^{[1
]}

机构：

[1] Washington Univ, Dept Elect & Syst Engn, Micro Nano Photon & Photon Mat Lab, St Louis, MO 63130 USA

来源：

APPLIED PHYSICS LETTERS | 2008年 / 93卷 / 20期

关键词：

coatings; microcavities; micromechanical resonators; micro-optics; polymers; red shift; silicon compounds; spectral line shift; thermal noise; whispering gallery modes;

D O I：

10.1063/1.3030986

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

We experimentally and theoretically characterize the thermal refraction effect in a silica microtoroid and demonstrate that such effect can be reduced or even eliminated by applying a thin layer of polydimethylsiloxane (PDMS) to the surface of the silica resonator. By increasing the coating thickness, the whispering gallery modes (WGMs) experience a transition from redshift to blueshift induced by thermal absorption. Experiment results demonstrate that at the thickness of 0.52 mu m, the fundamental WGM with observed Q factor of 1.5x10(6) shows no shift with the input optical power since the thermal refraction of the silica for this mode is compensated completely by the PDMS layer, which has an opposite thermal refraction effect. This work shows that the PDMS layer could be used to reduce thermal noise in high-Q silica microcavities for applications in sensing, lasing, and nonlinear optics.

引用

页数：3

共 21 条

[1] Label-free, single-molecule detection with optical microcavities [J].