CAJ | 학술논문

利用步进扫描时间分辨傅里叶变换红外光谱,研究了波长9.76μm GaAs/AlGaAs量子级联激光器的准连续波激射谱.在驱动电流周期内,时间上堆叠的发射谱能够观察到明显的光强自脉动现象.有源区中的自加热积累大大影响了电子的驰豫和输运性质.热引起的在注入区较高子能级中占据的载流子由于这些子能级与下一注入区的连续态形成共振条件而泄露,而耦合阱有源区中第四子能级的存在加快了这个过程.周期性破坏和恢复的共振条件所引起的载流子泄露在很大程度上导致了时域堆叠光谱的自脉动.
이용보진소묘시간분변부리협변환홍외광보,연구료파장9.76μm GaAs/AlGaAs양자급련격광기적준련속파격사보.재구동전류주기내,시간상퇴첩적발사보능구관찰도명현적광강자맥동현상.유원구중적자가열적루대대영향료전자적치예화수운성질.열인기적재주입구교고자능급중점거적재류자유우저사자능급여하일주입구적련속태형성공진조건이설로,이우합정유원구중제사자능급적존재가쾌료저개과정.주기성파배화회복적공진조건소인기적재류자설로재흔대정도상도치료시역퇴첩광보적자맥동.
Quasi-continuous wave lasing spectra of GaAs/AlGaAs quantum cascade lasers emitting at 9.76μm are characterized by step-scan time-resolved Fourier transform infrared spectroscopy. Pronounced self-pulsation in stacked emission spectra is observed in the driving current duration. Self-heating accumulation in the active region affects the electron relaxation and transport greatly. Thermally-induced carrier occupation of the higher sublevels in an injector can leak out through a resonant condition with the continuum states above the next injector,which will be facilitated by the fourth sublevel of the coupled quantum wells active region. The leaking process arising from the periodic breaking and recovering of resonant tunneling accounts for the physical mechanism of the selfpulsed effect in stacked emission spectra.