Abstract:
Heterodyne detection based on interband cascade lasers (ICL) has been demonstrated in a wide range of different applications. However, it is still often limited to bulky tabletop systems using individual components such as dual laser setups, beam shaping elements, and discrete detectors. In this work, a versatile integrated ICL platform is investigated for tackling this issue. A RF-optimized, two-section ICL approach is employed, consisting of a short section typically used for efficient modulation of the cavity field and a long gain section. Such a laser is operated in reversed mode, with the entire Fabry-Pérot waveguide utilized as a semiconductor optical amplifier (SOA) and the electrically separated short section as detector. Furthermore, a racetrack cavity is introduced as on-chip single-mode reference generator. The field of the racetrack cavity is coupled into the SOA waveguide via an 800 nm gap. By external injection of a single mode ICL operating at the appropriate wavelength, a heterodyne beating between the on-chip reference and the injected signal can be observed on the integrated detector section of the SOA-detector.
摘要:
基于带间级联激光器(ICL)的外差检测已在各种不同的应用中得到证明。然而,它通常仍然限于使用单个组件的笨重的桌面系统,例如双激光设置,光束整形元件,和离散探测器。在这项工作中,研究了一个通用的集成ICL平台来解决这个问题。RF优化,采用两段ICL方法,由通常用于有效调制腔场的短部分和长增益部分组成。这种激光器在反向模式下工作,将整个Fabry-Pérot波导用作半导体光学放大器(SOA),并将电隔离的短段用作检测器。此外,引入跑道腔作为片上单模参考发生器。跑道腔的场经由800nm间隙耦合到SOA波导中。通过外部注入工作在适当波长的单模ICL,可以在SOA检测器的集成检测器部分上观察到片上参考和注入信号之间的外差跳动。