LIGHT WAVEGUIDE COMMUNICATION SYSTEM

摘要

PURPOSE: To use an optical spectrum to the maximum by using a narrow band width laser light source. CONSTITUTION: The output signal of a dither oscillator 31 allows the emission frequency of a laser 23 to fluctuate in the neighborhood of a central frequency decided at first by currents from a bias current source 24 in the range of a narrow notch. As a result, the attenuation of a light inputted through a Bragg diffraction grating 17 to a light detector 28 is changed so that the actual laser emission frequency can be oscillated in the neighborhood of the central frequency. The output signal of a low pass filter 34 is changed so that a connected signal from an adding part 35 can be adjusted. Thus, an available optical spectrum can be used to the maximum by executing a dense optical FDM system using the optical fiber diffraction grating filter, and making an optical channel interval extremely close.