High-power picosecond terahertz-wave generation in photonic crystal fiber via four-wave mixing

We demonstrate picosecond terahertz (THz)-wave generation via four-wave mixing in an octagonal photonic crystal fiber (O-PCF). Perfect phase-matching is obtained at the pump wavelength of 1.55?μm and a generation scheme is proposed. Using this method, THz waves can be generated in the frequency range of 7.07-7.74?THz. Moreover, peak power of 2.55?W, average power of 1.53?mW, and peak conversion efficiency of more than -66.65?dB at 7.42?THz in a 6.25?cm long fiber are realized with a pump peak power of 2?kW.