Wideband and Low-Phase-Noise Chirped Pulses Generation Based on an Injection-Locked Optoelectronic Oscillator

We propose and demonstrate a photonic approach to generate wideband and low-phase-noise chirped pulses using an injection-locked optoelectronic oscillator (OEO). In the proposed system, the injection-locked OEO is implemented to generate low-phase-noise microwave waveforms, and photonic-assisted microwave frequency multiplication is performed to increase the bandwidth of the generated waveforms. In the experiment, a dual-polarization dual-drive Mach-Zehnder modulator (DP-DDMZM) is a key component, in which one sub-DDMZM is incorporated into the OEO loop and the other sub-DDMZM is used to perform frequency multiplication. As a demonstration, linearly chirped microwave pulse with a bandwidth as wide as 6 GHz and phase noise as low as -116 dBc/Hz@10 kHz is generated. The proposed system holds unique advantages of wide bandwidth and low phase noise, which is promising to be widely used in future high-resolution and multi-function radar systems.