All-in-One 10-W Peak Power Backward Terahertz-Wave Parametric Oscillator

Abstract

We have developed a frequency-tunable backward terahertz (THz)-wave parametric oscillator (BW-TPO) in a palm-sized compact package mountable on a robot. The driving laser source of a passively Q-switched Nd:YAG microchip laser, BW-TPO gain medium of a slant-strip-type periodically poled lithium niobate (PPLN) crystal, and all the optical components were assembled as an all-in-one module. The monochromatic backward-propagating THz-wave output with a maximum peak power of more than 10 W was obtained at 0.33 THz with a frequency tunable bandwidth of 60 GHz. Using this BW-TPO module mounted on a 2-axis motorized translation stage, THz-wave imaging in reflection geometry was performed, demonstrating the robust operation of the developed BW-TPO module ready for real-world THz-wave sensing applications.