Broadband and Precise Microwave Time Reversal Using a Single Linearly Chirped Fiber Bragg Grating

We propose and experimentally demonstrate a novel technique to achieve broadband and precise microwave time reversal using a single linearly chirped fiber Bragg grating (LCFBG). In the proposed approach, the time reversal is realized by the LCFBG that is operating in conjunction with a polarization beam splitter (PBS) to enable a triple use of the LCFBG with the microwave waveform entering the LCFBG from either the long or the short wavelength end. Since the LCFBG has a wide bandwidth and is used three times with exactly complementary and identical dispersion, broadband and precise microwave time reversal is ensured. A theoretical analysis is performed which is validated by simulations and an experiment. The time reversal of three different microwave waveforms with a bandwidth over 4 GHz and a time duration of approximately 10 ns is demonstrated.