Effect of excited-state transitions on the threshold characteristics of a quantum dot laser

被引：6

作者：

Asryan, LV ^{[1
]}

Grundmann, M ^{[1
]}

Ledentsov, NN ^{[1
]}

Stier, O ^{[1
]}

Suris, RA ^{[1
]}

Bimberg, D ^{[1
]}

机构：

[1] Tech Univ, D-10623 Berlin, Germany

来源：

PHYSICS AND SIMULATION OF OPTOELECTRONIC DEVICES VIII, PTS 1 AND 2 | 2000年 / 3944卷

关键词：

semiconductor heterojunctions; semiconductor lasers; quantum well and quantum dot lasers;

D O I：

10.1117/12.391491

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

Theoretical study of threshold characteristics of a quantum dot (QD) laser in the presence of excited-state transitions is given. The effect of microscopic parameters (degeneracy factor and overlap integral for a transition) on the gain is discussed. An analytical equation for the gain spectrum is derived in an explicit form. Transformation of the gain spectrum with the injection current is analyzed. The threshold current density is calculated as a function of the total losses. The conditions for a smooth or step-like change in the lasing wavelength with the losses are formulated. Threshold characteristics of a laser based on self-assembled pyramidal InAs QDs in GaAs matrix are simulated. A small overlap integral for transitions in such QDs (and hence large spontaneous radiative lifetime) is shown to be a main possible reason for a low value of the maximum single-layer modal gain of the respective structure which is deficient to attain lasing at moderately short (several hundreds of micrometers) cavity lengths.

引用

页码：823 / 834

页数：12

共 18 条

[11] Optical characteristics of 1.24-μm InAs quantum-dot laser diodes [J].