Indirect Sub-Harmonic Optical Injection Locking of a Millimeter Wave IMPATT Oscillator

This paper presents results of indirect optical injection locking of a free-running 38GHz (Ka-band) IMPATT oscillator over the locking range of 2 to 132MHz, depending on the injected power level (amplifier gain). In this experiment, The nonlinearity of the both laser diode and the IMPATT, are exploited to achieve twelfth sub-harmonic injection locking. Methods by which optical links may be extended into 60 and 90GHz are demonstrated.