Sub-terahertz frequency generation in non-resonant Fabry-Pérot cavity

A method to generate a continuous train of optical ultrashort pulses (USP) with sub-terahertz (sub-THz) repetition rate by utilizing the non-resonant Fabry-Pérot cavity (NRFPC) is explored. Analytical results reveal the possibility to generate widely tunable repetition rate USP signals via a tunable NRFPC from few tens of megahertz to sub-terahertz regime. The stable output repetition rate of the USP is a function of NRFPC length in air (Lair), which can be tuned. The maximum USP output repetition rate is partly limited by both pulse width of USP in the NRFPC and the minimum NRFPC length in air. Output pulse train decay rate depends on the reflectivity of both input and output couplers. Jitter-free USP output can be achieved by setting the ratio of input pulse repetition period and pulse's round trip time in NRFPC equal to any non-zero positive integer.