Compact THz-radiation source consisting of a bulk semiconductor, a mode-locked fiber laser, and a 2 T permanent magnet

A compact THz-radiation source using an InAs semiconductor is demonstrated with a turn-key femtosecond fiber laser as an excitation source and a newly designed 2 T permanent magnet. By using a newly designed magnetic circuit, a compact permanent magnet which can exceed the remanence magnetic field was obtained. This compact source is sufficiently intense for absorption spectroscopy.