Few-cycle THz Pulse Generation in DSTMS Crystal Pumped by a 8.3-MHz Amplified Mamyshev Oscillator

Abstract: Mamyshev oscillators are an emerging class of ultrafast fiber lasers that support exceptionally broadband spectra and few-femtosecond pulse durations, making them well-suited for nonlinear frequency conversion. Despite this potential, THz generation using Mamyshev oscillators has not been demonstrated to date. In this work, we report the generation of THz few-cycle at 8.3 MHz repetition rate via optical rectification of a 31-fs pulse duration, 1-W average power amplified Mamyshev oscillator in a 190-um-thick DSTMS organic crystal. We measured a THz average power of 40 uW and a spectral bandwidth of 4 THz. To further investigate the advantage of combining Mamyshev oscillator and organic crystals for THz generation at multi-MHz repetition rate, we compared the THz pulses with those generated using a conventional inorganic 500 um-thick GaP crystal, obtaining comparable bandwidth, but 20 times lower power with respect to DSTMS.