High-speed operation of single-mode tunable quantum cascade laser based on ultra-short resonant cavity

Yuhong Zhou,Shenqiang Zhai,Zhanguo Wang,Fengqi Liu,Junqi Liu,Shuman Liu,Ning Zhuo,Lijun Wang,Jinchuan Zhang

doi:10.1063/5.0036219

Abstract

We have demonstrated a room temperature, low power consumption, high-speed, and single-mode tunable quantum cascade laser at λ ∼ 4.6 µm. Combining a 300 µm buried hetero-structure ultra-short cavity with optimized facet coatings, a single-mode tuning range covering ∼40 nm is obtained at room temperature under low electrical power consumption below 1.1 W. The single-mode emission is observed with more than 25 dB side mode suppression ratio in the whole tuning range. The high frequency modulation is achieved with a microwave package, resulting in the −3 dB cutoff frequency of 5.6 GHz.

Highlights

Scitation.org/journal/adv a modulation bandwidth of up to 23.5 GHz and 25.5 GHz.14 A room temperature single-mode buried grating quantum cascade laser with a thick SiO2 insulating layer was demonstrated to have a flat frequency response of up to roughly 3 GHz.15 emergence of more promising technologies toward yielding room temperature high-speed Quantum cascade lasers (QCLs) with high single-mode tunability is still expected for advancing the development of Chirped laser dispersion spectroscopy (CLaDS) and free-space optical communication (FSOC)
Room temperature, high-frequency directly modulated single-mode QCLs are of particular interest for CLaDS and FSOC
A single-mode distributed feedback (DFB) QCL integrated with a three-terminal microwave coplanar waveguide structure displayed scitation.org/journal/adv a modulation bandwidth of up to 23.5 GHz and 25.5 GHz

Summary

Introduction

Room temperature, high-frequency directly modulated single-mode QCLs are of particular interest for CLaDS and FSOC. A chalcogenide lateral waveguide QCL maintained a modulation response of up to roughly 7 GHz at a temperature of 20 K.13 A flat frequency response of up to ∼15 GHz for mid-infrared QCLs embedded into the microstrip line operating at 77 K was obtained.7 A single-mode distributed feedback (DFB) QCL integrated with a three-terminal microwave coplanar waveguide structure displayed scitation.org/journal/adv a modulation bandwidth of up to 23.5 GHz (optical) and 25.5 GHz (electrical).14 A room temperature single-mode buried grating quantum cascade laser with a thick SiO2 insulating layer was demonstrated to have a flat frequency response of up to roughly 3 GHz.15 emergence of more promising technologies toward yielding room temperature high-speed QCLs with high single-mode tunability is still expected for advancing the development of CLaDS and FSOC.

Results

Conclusion