DEMONSTRATION OF A NOVEL WIDE-BAND OPTICAL SIGNAL GENERATOR BY DEEP PHASE MODULATION IN A FIBER COUPLER

Abstract

A simple method for wide bandwidth optical signal generation has been realized by applying a deep phase modulation signal in a fiber coupler which acts as an all-fiber Michelson interferometer. The output of the interferometer displays a discrete spectrum with a nearly leveled output and frequency bandwidth up to a hundred times that of the frequency of the modulation signal. In this first demonstration, we have generated frequency components up to 4 MHz (with external modulation) and 50 MHz (by direct modulation of the laser diode) respectively. Multigigahertz operation is possible in the future with wideband integrated-optic phase modulators.