Microwave generation with an inner-modulated laser and parallel Mach-Zehnder interferometers

Using an inner-frequency-modulated semiconductor laser, two parallel Mach-Zehnder delay-line interferometers and feedback control loop technique, we generate microwaves. The frequency of the Littrow-structure semiconductor laser is modified by a lead zirconate titanate actuator that covers a wideband modulating range. One long delay-line interferometer generates microwaves; the second short delay-line interferometer controls the linearity of the modulate laser and assures microwave stability by a feedback loop. Thus, this method, in theory, should produce more than one hundred GHz microwave. We experimentally generated 1.743 GHz to 5.134 GHz microwaves. This technology opens a new path for developments in microwave photonics.