Abstract

The terahertz (THz) quantum cascade laser (QCL) [1] is finding extensive use in a range of important applications including spectroscopy, imaging, astrophysics and sensing, in a frequency range that has been traditionally challenging to explore. For many experiments, especially where highly absorbing samples or large optical paths are involved, absolute device power is often a limiting factor, with peak powers commonly on the order of 10s mW required. As such, a compact and simple method of THz radiation amplification would be of great benefit to many across the research field. Efforts in this direction have produced master-oscillator power amplifier schemes [2], as well as gain-switched devices [3] for ultra-fast pulse amplification. However, the master-oscillator schemes employ tilted facets, consequently distorting beam profiles, whilst gain-switching devices are limited to only ultra-short pulse amplification set-ups.

© 2015 IEEE