WAVELENGTH MULTIPLEX LIGHT SIGNAL TRANSMISSION APPARATUS

摘要

PROBLEM TO BE SOLVED: To make it possible to utilize a mode locking semiconductor laser as a multiple wavelength light source by providing the apparatus with means for discretely executing the optical phase transition of the continuous monochromatic light of the respective oscillation modes of this mode locking semiconductor laser. SOLUTION: This wavelength multiplex light signal transmission apparatus is provided with the optical phase transition means 26 for discretely executing the optical phase transition of the continuous monochromatic light of the respective oscillation modes before or behind an external modulator 18. The reference light from a reference light source 11 is amplified in an optical amplifier 23. Spontaneous emission light (ASE) in the optical amplifier 23 is removed from this light by an optical filter 24 and after the light is modulated by the modulator 25, the light is injected and locked into the mode locking semiconductor laser 12. The absolute wavelength is repeated by the light injection, by which frequencies are simultaneously stabilized. The pulses consisting of the multiple wavelength light outputted from the mode locking semiconductor laser 12 are branched by each of the modes (light frequencies) by an AWG 15 and are discretely subjected to optical frequency conversion by respective optical frequency shifters in such a manner that irregular spacings are attained. Then, the power penalty is greatly ameliorated near the zero dispersion wavelength as compared with the array of equal spacings.