GENERATION OF SHORT OPTICAL PULSES USING STRONGLY COMPLEX COUPLED DFB LASERS

摘要

A compact source capable of generating continuously tunable high frequency microwave radiation and short optical pulses is invented. It includes a laser structure having two lasers formed on the same substrate which simultaneously operate at different longitudinal modes. Each laser has a complex coupled grating. The lasers have a common active medium and shared optical path and provide mutual light injection into each other which results in generation of a beat signal. The beat frequency is defined by spacing between the laser modes and may be continuously tuned by current injection and/or temperature variation. To form a train of short optical pulses, the beat signal is either further sent to a saturable absorber followed by a semiconductor optical amplifier, or sent directly into an optical compressor. An embodiment where N short pulse optical trains, each at frequency f, are combined so as to interleave and form one short pulse optical train at frequency Nf, is also provided.