A Proposal and Demonstration for Photonic Generation of a Microwave Signal by Incorporating a Microring Resonator

A proposal for photonic generation of a microwave signal is presented by employing a dual wavelength erbium-doped fibre ring laser. In the laser, a microring resonator is cascaded with a tunable bandpass filter to serve as a dual-wavelength selector, an unpumped polarization maintaining erbium-doped fibre is used as a saturable absorber. By replacing the microring resonator with a delay interferometer to verify the proposal, a wavelength-tunable dual wavelength single longitudinal mode laser is demonstrated, and a microwave signal at 10.01GHz with a linewidth of less than 25kHz is obtained by beating the two wavelengths at a photodetector.