Linearly Chirped Microwave Generation Using a Monolithic Integrated Amplified Feedback Laser

A linearly chirped microwave waveform (LCMW) generator based on a monolithically integrated dual-mode amplified feedback laser (AFL) is demonstrated. The proposed LCMW generator is very simple, only consisting of an AFL, an arbitrary waveform generator, and a photodetector. By applying a sweeping signal to the amplifier section of the AFL, the beating frequency of the AFL's output can be changed in a chirped manner. LCMW is experimentally demonstrated using a heterodyne-beating technique. The measured microwave waveform has a pulse duration of 1 μs, a bandwidth of 3.3 GHz (ranging from 31.5 to 34.8 GHz), corresponding to a time-bandwidth product of 3.3 × 10
³
and a compression ratio of 2.6 × 10
³
.