A simple approach for photonic generation of microwave signal using a dual-wavelength single-longitudinal-mode
erbium-doped fiber ring laser is proposed and demonstrated. For the first time, a chirped moiré fiber Bragg grating
(CMFBG) filter with ultra-narrow transmission band and a chirped fiber Bragg grating are used to select the longitudinal
mode. The stable single longitudinal mode operation is guaranteed by the combination of the CMFBG filter and 3m
unpumped erbium-doped fiber acting as a saturable absorber. Stable dual-wavelength single longitudinal mode fiber
laser with a wavelength spacing of approximately 0.140nm are experimentally realized. By beating the dual-wavelength
fiber laser at a photodetector, photonic generation of microwave signal at 17.682GHz is successfully obtained.