Diverse waveform generation using semiconductor lasers for radar and microwave applications

The possibility of using semiconductor lasers to conveniently generate diverse microwave waveforms for radar and microwave applications is studied both numerically and experimentally. Such waveforms are generated from the dynamical states of semiconductor lasers in different perturbation schemes and varying operating conditions. Using an optical injection scheme, broad-band chaotic microwave waveforms and tunable narrow-band harmonic microwaves over a broad frequency range can be generated. Using an optoelectronic feedback scheme, chaotic pulsing, regular pulsing, frequency-locked pulsing, and quasi-periodic pulsing waveforms are generated. These optically generated microwave waveforms can be easily amplified and radiated out using microwave amplifiers and antennas. The power spectra, time series, and autocorrelation traces of such waveforms are studied. The peak-sidelobe level is calculated to quantitatively compare the correlation characteristics of these waveforms. A broad-band chaotic waveform with a clean single-spike δ-function-like correlation profile useful for radar and other applications that demand unambiguous correlation profile is demonstrated experimentally.