Tilted Fiber Bragg Grating for Chirped Microwave Waveform Generation

A tilted fiber Bragg grating (TFBG) as an optical spectral shaper to generate a chirped microwave waveform in a spectral-shaping and wavelength-to-time (SS-WTT) mapping system is proposed and demonstrated. The key component in the system is the TFBG, which has multiple resonant peaks with linearly increasing spacing in its transmission spectrum. By incorporating a TFBG into an SS-WTT system, a chirped microwave waveform is generated with the chirp rate determined by the tilt angle of the TFBG. A proof-of-concept experiment is carried out. Two TFBGs with tilt angles of 10 and 4 are fabricated and employed to generate two chirped microwave waveforms with chirp rates of 0.00700 and 0.05956 GHz/ps, respectively.