Optoelectronic down-conversion by four-wave mixing in a highly nonlinear fiber for millimeter-wave and THz phase-locking

摘要

Optoelectronic down-conversion of a THz optical beatnote to a RF intermediatefrequency is performed with a standard Mach-Zehnder modulator followed by azero dispersion-slope fiber. The two interleaved optical spectra obtained byfour-wave mixing are shown to contain more than 75 harmonics enabling toconveniently recover the phase noise of a beatnote at 770 GHz at around 500MHz. This four-wave mixing down-conversion technique is implemented in atwo-frequency solid-state laser in order to directly phase-lock its 168 GHzbeatnote to a 10 MHz local oscillator.