Low-Threshold and Wavelength-Tunable InGaN Tubular WGM Laser Embedded in a Flexible Substrate

Crystals

Feng Yun¹  Peng Hu¹  Zhenhuan Tian¹  Ye Zhang¹  Shengnan Zhang¹  Yufeng Li¹ 

[1] Shaanxi Provincial Key Laboratory of Photonics & Information Technology, Xi’an Jiaotong University, Xi’an 710049, China;

关键词: WGM;    microtube;    cavity;   

DOI  :  10.3390/cryst11101251

来源: DOAJ

【 摘 要 】

We have fabricated a tubular whispering gallery mode laser based on InGaN/GaN quantum wells and transferred it onto a flexible substrate. Compared with those without the transferring processes, the threshold energy density was reduced by 60%, at about 25.55 µJ/cm², while a high-quality factor of >15,000 was obtained. Finite-difference time-domain simulation demonstrated that such a low threshold energy density can be attributed to the decreased mode volume, from 1.32 × 10⁻³ μm³ to 6.92 × 10⁻⁴ μm³. The wavelength dependences on strain were found to be 5.83 nm, 1.38 nm, and 2.39 nm per stretching unit ε in the X, Y, and Z directions, respectively. Such strain sensitivity was attributed to the deformation of the GaN microtube and the change in the refractive index of the PDMS.

【 授权许可】

Unknown