Compact THz source system using quantum cascade lasers

Abstract

Recently, terahertz (THz) technology is being advanced towards industrial application such as gas sensing or nondestructive testing and so forth. With progress in device technology, sources and detectors operating in the THz region have been developed. By combining the THz detector with a high power THz source, monitor systems for the applications mentioned above can be constructed. For this purpose, compact systems, composed of a high-power source and a high-sensitive detector, are required, which need to have small footprint. For the detector, compact devices operating at room temperature such as pyroelectric detectors, THz cameras and so forth are commercially available. On the other hand, for source devices, quantum cascade lasers (QCLs), resonant tunneling diodes (RTDs), and frequency multipliers have been developed as compact sources. Among them, the THz-QCL is a good candidate for the THz source, because it can emit high power THz radiation with high spectral purity. However, because the THz-QCL operates at low-temperature, the THz-QCL source system tends to be a large size. In this paper, we report on a compact THz source system based on a THz-QCL.