Virtual Gires-Tournois etalons realized with phase-modulated wideband chirped fiber gratings

Arbitrary-Order Photonic Hilbert Transformers Based on Phase-Modulated Fiber Bragg Gratings in Transmission

Photonic Hilbert transformers are fundamental components for optical computing and signal processing. Here, for the first time we propose all-optical arbitrary-order Hilbert transformers using phase-modulated fiber Bragg gratings (PM-FBGs) in transmission to our best knowledge. The PM-FBG is a kind of fiber grating, whose coupling strength remains almost uniform and period varies along the fiber length. For demonstration, we have designed and numerically simulated 0.5th-order, first-order, and 1.5th-order photonic Hilbert transformers, respectively. The profiles of those PM-FBGs are obtained employing quasi-Newton optimization algorithm. Simulation results show that the designed three Hilbert transformers are all in good agreement with the ideal results in bandwidths up to 500 GHz and can tolerate a large range of input pulse width.

Proposal and design of phase-modulated fiber gratings in transmission for pulse shaping

An approach to pulse shaping using a phase-modulated fiber Bragg grating (FBG) in transmission is proposed and designed. We show that phase-modulated FBGs can provide transmission responses suitable for pulse shaping applications, offering important technological feasibility benefits, since the coupling strength remains basically uniform in the grating. Moreover, this approach retains the substantial advantages of FBGs in transmission, such as optimum energy efficiency, no requirement for an optical circulator, and robustness against fabrication errors.