An all-optical tunable polymer WGM laser pumped by a laser diode

Ben Niu; Xiaoyu Shi; Kun Ge; Jun Ruan; Zhiyang Xu; Shuai Zhang; Dan Guo; Tianrui Zhai

doi:10.1039/d2na00025c

An all-optical tunable polymer WGM laser pumped by a laser diode

Nanoscale Adv. 2022 Mar 30;4(9):2153-2158. doi: 10.1039/d2na00025c. eCollection 2022 May 3.

Authors

Ben Niu¹, Xiaoyu Shi¹, Kun Ge¹, Jun Ruan¹, Zhiyang Xu¹, Shuai Zhang¹, Dan Guo¹, Tianrui Zhai¹

Affiliation

¹ College of Physics and Optoelectronics, Faculty of Science, Beijing University of Technology Beijing 100124 China trzhai@bjut.edu.cn.

Abstract

An all-optical tunable whispering gallery mode (WGM) laser pumped by a laser diode is proposed. The laser is fabricated by filling a silica capillary with a light-emitting conjugated polymer solution. Based on the thermo-optic effect of the hydroxyl groups in the polymer and capillary, the effective refractive index of the WGM cavity changes by the auxiliary irradiation of the laser, and the wavelength of the WGM mode shifts correspondingly. The emission wavelength was continuously tuned over 13 nm with the irradiation power intensity changing from 0 to 22.41 W cm^-2, showing a corresponding tuning rate of 0.58 nm W^-1 cm^-2. The wavelength tuning process has a fast response time that is within 2.8 s. It shows strong stability, with the output intensity showing no obvious attenuation after 100 minutes of operation. The proposed laser exhibits good repeatability, stability and high tuning efficiency, and could be applied as a light source for on-chip devices.