Fiber-fed 60-GHz self-heterodyne system using a self-oscillating harmonic optoelectronic mixer based on a CMOS-compatible APD

We demonstrate a fiber-fed 60-GHz self-heterodyne system using a self-oscillating harmonic optoelectronic mixer (SO-HOM) based on a Si avalanche photodetector (APD) fabricated with 0.18 μm standard complementary metal-oxide-semiconductor (CMOS) process. The proposed SO-HOM consists of a CMOS-compatible APD and a feedback electrical loop for self-oscillation. It simultaneously performs photodetection and harmonic optoelectronic frequency up-conversion of photodetected data signals to the 2
^nd
harmonic self-oscillation frequency band. We successfully demonstrate data transmission of 5 MS/s 32 quadrature amplitude modulation signals in a 60-GHz band without any local oscillators operating in millimeter-wave bands.