Multiple-bipolar-tap tunable spectrum sliced microwave photonic filter
ABSTRACT A spectrum sliced microwave photonic signal processor structure, which is all-fiber based and features simplicity, together with the ability to realize tunability, reconfigurability, bipolar taps, and multiple-tap rf filtering, is presented. It is based on thermally controlled optical slicing filters induced into two linearly chirped fiber Bragg gratings. Experimental results demonstrate the realization of versatile microwave photonic filters with frequency tunable, reconfiguration, and bipolar-tap generation capabilities.
Conference Paper: Recent advances in photonic signal processing of microwave signals[Show abstract] [Hide abstract]
ABSTRACT: Photonic signal processing allows direct processing of high frequency signals that are already in the optical domain, and offers a new powerful paradigm for processing high bandwidth signals to overcome the inherent bottlenecks caused by limited sampling speeds in conventional electrical signal processors. Recent new developments in wideband signal processing, which address the challenges of realizing photonic signal processors without dispersion induced RF distortion, having tunable and reconfigurable operation, high resolution performance, and all-optical complex coefficients for arbitrary signal processing, are presented.Signal Processing, Communications and Computing (ICSPCC), 2011 IEEE International Conference on; 01/2011
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ABSTRACT: A tunable negative-tap photonic microwave filter using a cladding-mode coupler together with optical injection locking of large wavelength detuning is demonstrated. Continuous and precise tunability of the filter is realized by physically sliding a pair of bare fibers inside the cladding-mode coupler. Signal inversion for the negative tap is achieved by optical injection locking of a single-mode semiconductor laser. To couple light into and out of the cladding-mode coupler, a pair of matching long-period fiber gratings is employed. The large bandwidth of the gratings requires injection locking of an exceptionally large wavelength detuning that has never been demonstrated before. Experimentally, injection locking with wavelength detuning as large as 27 nm was achieved, which corresponded to locking the 36-th side mode. Microwave filtering with a free-spectral range tunable from 88.6 MHz to 1.57 GHz and a notch depth larger than 35 dB was obtained.Optics Express 06/2011; 19(13):12045-52. DOI:10.1364/OE.19.012045 · 3.53 Impact Factor
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ABSTRACT: Recently we have proposed a dispersion controlled spectrum slicing technique, which provides both spectrum slicing of the broadband source and phase control function that impresses localized dispersion for the optical slices. In this paper, we extend this earlier concept by deriving transfer functions and investigating the performance of the dispersion controlled spectrum sliced microwave photonic signal processor for various slice characteristics. Through analysis, simulation and experimental results, we demonstrate that the RF filter performance at high frequency of operation can be greatly enhanced, for arbitrary spectrum slice shapes, slice bandwidths and various filter free spectral range values.Microwave Photonics (MWP), 2012 International Topical Meeting on; 01/2012