Generation of Highly Stable Millimeter Waves With Low Phase Noise and Narrow Linewidth

We present a novel stabilization technique for millimeter (mm) waves produced by interfering two spectral lines of a frequency comb generated by a femtosecond fiber laser. To compensate the lasers repetition rate drift, the mm-wave is stabilized through the modulation of one extracted comb line. Thus, no access to the lasers cavity is necessary. This leads to a stable and high-quality mm-wave with a spectral linewidth of 1 Hz and a phase noise of -134 dBc/Hz at 10 kHz carrier offset via the software stabilization technique. The long-term stability shows a drift of the generated frequencies as low as 1 Hz over more than 40 min with an analog circuit.