基于太赫兹量子阱探测器的太赫兹量子级联激光器发射谱研究

Emission spectra of terahertz quantum-cascade lasers based on the terahertz quantum-well photodetectors

采用一个光谱匹配的太赫兹(THz)量子阱探测器(QWP)研究了一激射频率约为4.1THz的THz量子级联激光器(QCL)在不同驱动电流下的发射谱,分析了测量得到的发射谱谱型和谱峰位置,根据测量的发射谱估算了太赫兹量子级联激光器发射功率随驱动电流变化的情况,从而得到了THzQCL激射的电流密度范围及其阈值电流密度.文中还研究了THzQWP在不同温度下对THzQCL激光辐射的响应特性.研究结果表明,THzQWP在表征THzQCL的发射谱方面是一种很好的探测器,并有望成为未来THz通信中的接收装置.

The emission of a 4.1 THz quantum cascade laser（THz QCL） has been measured by a spectrally-matching terahertz quantum-well photodetector（THz QWP）.The measured emission spectra have been analyzed with respect to the spectral shape and peak position.The relative light power of the laser under different drive currents have been estimated from the emission spectra and then the lasing domain and threshold current density of the laser has been determined.The temperature-dependent response of THz QWP to the laser has also been investigated.The analyzed results indicate that the THz QWPs could be a good detector for characterizing the emission properties of the THz QCLs and may be the receivers in the terahertz communications.