Two-branch double-stage phase-diversity (DSPD) coherent receiver using a 3/spl times/3 fiber coupler

We propose a novel two-branch double-stage phase-diversity receiver. It uses a 3/spl times/3 fiber coupler as a 120/spl deg/ optical hybrid, and features a fiber-type optical circuit and a simple electrical circuit. Experimental confirmation of the principle and demonstration of suppression of the image-band beat noise from fiber amplifiers are shown.<
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