Experimental demonstration of Bi₂Te₃ saturable absorption with whispering gallery modes in an InGaAsP microdisk laser

Abstract

In this study, Bi2Te3 cluster was applied as a saturable absorber to investigate the mode-locking behavior of InGaAsP multiple quantum wells (MQWs) whispering gallery mode (WGM). Under optical excitation, the ultralow saturation absorption of Bi2Te3 from bulk state had modulated the intensity inside the microdisk, multi-lasing at different wavelengths with equal spectral spacing was realized. The achieved pulse repetition rate was as high as an estimated 4 THz. Additionally, a clear degenerate breaking was observed with a frequency shift of approximately 1 THz for each lasing mode. To the best of our knowledge, this is the first demonstration of a passively mode-locked WGM laser. These findings may have applications in dual-comb device.

Photonic Crystal Circular Nanobeam Cavity Laser with Type-II GaSb/GaAs Quantum Rings as Gain Material

“…However, in this work, we focused only on the smaller photonic crystal cavities for the ultra-small mode volume and lower lasing threshold. In the future, the room temperature CW operated sub-micrometer PhC cavity laser with type-II QRs can be expected by placing laser cavities on the top of the high thermal conductive substrates [75][76][77][78] .…”