Programmable Correction of Fiber Bragg Grating Delay Ripple for RF Photonic Filtering

Abstract

We present the correction of chirped fiber Bragg grating (FBG) group delay ripple (GDR) for improved sidelobe suppression in a dispersion and optical frequency comb-based radio-frequency (RF) photonic filter. The measured GDR is directly compensated by programming the spectral phase of an optical line-by-line pulse shaper on an optical frequency comb. As a result, the degradation in the sidelobe suppression of the RF photonic filter response is reduced by $\sim 10$ dB. Compared with optical fiber-based dispersion, the much shorter length of the chirped FBG should substantially reduce the latency of dispersion-based RF photonic filters.