Fig. 1: Schematic of an electrically pumped THz PEPC QCL and scanning electron microscope (SEM) images of a PEPC resonator.
From: High brightness terahertz quantum cascade laser with near-diffraction-limited Gaussian beam
a Schematic diagram of a THz PEPC QCL structure with non-etched active region scheme. The PEPC resonator was constructed by using metal and air interface, adopting a non-etched active region scheme. b Top-view SEM images of the fabricated square PEPC resonator (upper panel) and the absorption boundary around an electrode (lower panel). The white bar represents 100 μm. Two spaced electrodes on each side of the device are fabricated for uniform current injection. The outer n+ layer on the square edge of the cavity is retained as the absorption boundary
