Compact Optical Curvature Sensor with a Flexible Microdisk Laser on a Polymer Substrate

Wan Kuang, Boise State University
M. H. Shih, National Chiao-Tung University, Taiwan
K. S. Hsu, National Chiao-Tung University, Taiwan
Y. C. Yang, Academia Sinica, Taiwan
Y. C. Wang, National Tsing-Hua University, Taiwan
S. K. Tsai, National Tsing-Hua University, Taiwan
Y. C. Liu, National Tsing-Hua University, Taiwan
Z. C. Chang, National Tsing-Hua University, Taiwan
M. C. Wu, National Tsing-Hua University, Taiwan

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This is an author-produced, peer-reviewed version of this article. The final, definitive version of this document can be found online at Optics Letters, published by Optical Society of America. Copyright restrictions may apply. DOI: 10.1364/OL.34.002733

Abstract

In this paper, a chip-scale compact optical curvature sensor was demonstrated. It consists of a low threshold InGaAsP microdisk laser on a flexible polydimethylsiloxane polymer substrate. The curvature dependence of lasing wavelength was characterized by bending the cavity at different bending radii. The measurements showed that the lasing wavelength decreases monotonously with an increasing bending curvature. A good agreement between experiment and three-dimensional finite-difference time-domain simulation was also obtained. The sensitivity of the compact device to the bending curvature is -23.7 nm/mm form the experiment.