Intersubband photocurrent in the InAs/AlSb mid-infrared quantum cascade laser (QCL) device is measured. To characterize subband energies in a fabricated and functioning QCL laser device, Fourier-transform infrared (FTIR) microscope is used to focus the probe light on the cleaved mirror of QCL. Photocurrent associated with intersubband transitions in the active layer are observed up to room temperature and the origin of peaks is identified by numerical simulation, which demonstrates the potential as a characterization tool for QCL devices.
ASJC Scopus subject areas
- Physics and Astronomy(all)