LIGHT TRANSMITTER AND LIGHT TRANSMISSION METHOD AND POLARIZED LIGHT DIVISION MULTIPLEXED OPTICAL SIGNAL GENERATOR

摘要

PROBLEM TO BE SOLVED: To generate a polarized light division multiplexed optical pulse train with a simple structure. SOLUTION: A data generation circuit 10 generates transmission data synchronously with a clock (frequency fc) outputted from a clock generation circuit 12. A light source 14 generates laser light and applies it to a data modulator 16. The data modulator 16 modulates the intensity of laser light from the light source 4 in accordance with transmission data from the data generation circuit 10 to generate an optical signal of an RZ optical pulse train for carrying the transmission data. The generated optical pulse train is inputted to a phase modulator 20 through a polarizer 18 in the direction of polarization of 45 deg. to the phase modulator 20. A frequency divider 22 divides the frequency of the clock outputted from the clock generation circuit 12 into a half frequency fc/2. The output of the frequency divider 22 is applied to the phase modulator 20 through a delay circuit 24. The phase modulator 20 gives 0 or πphase change to the x-direction component of the optical pulse train inputted from the polarizer 18 in accordance with a driving signal from the delay circuit 24 with respect to each bit section.