Wu, H.-H.H.-H.WuWang, C.-L.C.-L.WangChang, C.-S.C.-S.ChangPan, C.-L.C.-L.PanGONG-RU LIN2020-06-112020-06-111994https://www.scopus.com/inward/record.uri?eid=2-s2.0-0028441090&doi=10.1143%2fJJAP.33.L760&partnerID=40&md5=505ef9525600a9b86d68cef5b83b9246We present a new, more versatile scheme for maintaining phase coherence between optical probe pulses and microwave signals under test in a laser-diode-based optoelectronic sampling system. This approach takes advantage of the relative ease of changing the repetition rate of the gain-switched laser diode (GSLD). The microwave signal to be sampled is used as the clock signal for phase-locking of a voltage controlled-oscillator (VCO) which drives the GSLD. Phase-tracking and display of waveforms at frequencies up to 8 GHz have been realized. It is also shown that lower phase noise sidebands for the phase-locked VCO can be realized by locking the higher harmonics of the laser pulse to the microwave clock. © 1994 IOP Publishing Ltd.Electro-optic sampling; Harmonic mixing; Laser and laser applications; Optical-microwave interactions; Optoelectronic phase-locked loop[SDGs]SDG7Electric waveforms; Harmonic generation; Microwaves; Phase locked loops; Semiconductor lasers; Signal processing; Synchronization; Variable frequency oscillators; Electrooptic sampling; Gain switched laser diodes; Harmonic mixing; Optical microwave interactions; Optoelectronic phase tracking; Phase coherence; Optoelectronic devicesjournal article10.1143/JJAP.33.L7602-s2.0-0028441090