Generation of difference-frequency radiation in the far- and mid-IR ranges in a two-chip laser based on gallium arsenide on a germanium substrate

The possibility of efficient generation of difference-frequency radiation in the far- and mid-IR ranges in a two-chip laser based on gallium arsenide grown on a germanium substrate is considered. It is shown that a laser with a waveguide of width 100 μm emitting 1 W in the near-IR range can generate ~40 μW at the difference frequency in the region 5 — 50 THz at room temperature.