Millimeter-wave generation through phase-locking of two modulation sidebands of a pair of laser diodes

In this letter, a novel scheme has been proposed for the generation of tunable millimeter (mm)-wave signals by optical mixing of two coherent lightwaves from two semiconductor lasers in a wide-band photodiode. The coherency of the two laser diodes (LDs) is achieved through phase-locking of two modulation sidebands, one from each LD, in an optoelectronic phase-locked loop (OEPLL). Calculated mm-wave power at a frequency of 250 GHz is -20 dBm. By varying the power and frequency of the microwave drive applied to the optical phase modulator in the OEPLL, the frequency of the generated mm-wave signal can be varied over a wide range.