[20p-E204-1~11] 3.13 Semiconductor optical devices

[20p-E204-3] Gain enhancement of quantum cascade lasers by simulation with nonequilibrium Green's function

〇Hirotaka Tanimura¹, Shigeyuki Takagi¹, Tsutomu Kakuno², Rei Hashimoto², Kei Kaneko², Shinji Saito² (1.Tokyo Univ. of Tech., 2.Toshiba)

Keywords:quantum cascade laser

We designed the semiconductor active layer of quantum cascade laser (QCL) by simulation using nonequilibrium Green's function. With the wavelength of 4 mm as the design goal, we aimed to improve the gain.The design of the structure in which the improvement of the gain was remarkable was "a structure in which the thickness of the barrier of the active region was reduced by 30%" and "a structure in which the composition of Al of the barrier was lowered by 14%".In addition, the mechanism of gain improvement is analyzed in detail from the oscillator strength and probability density.