Patent ID: 6118562
Filing Date: 2000-09-12
Classification: H01S,H04B

Abstract:
A wavelength aligning apparatus for aligning a wavelength of a light source in a multiple channel optical transmission system using a wave splitting multiple transmission technique, comprising:a plurality of light sources each having a central wavelength;a plurality of laser diode drivers for controlling the central wavelength of each of said light sources for generating lights in accordance with controls of said laser diode drivers;a plurality of signal generators for applying a signal spaced-apart at a predetermined interval near a predetermined frequency to a bias current of the plurality of said light sources and dithering the central wavelengths of each of said light sources;an arrayed waveguide grating connected to each of said light sources;a temperature controller connected to said arrayed waveguide grating;an optical fiber coupler disposed in an output terminal of the arrayed waveguide grating for dividing a difference signal from said arrayed waveguide grating into a transmission signal and an incoming signal;a plurality of locking amplifiers connected so as to receive the income signal from said optical fiber coupler;a plurality of proportional/integration/differentiating units, each of said proportional/integration/differentiating units being connected to each of said locking amplifiers; anda plurality of superposing units connected to said signal generators, said proportional/integration/differentiating units, and said laser diode drivers;wherein said arrayed waveguide grating causes a variation difference signal between a reference wavelength and the dithering of the central wavelength;said temperature controller maintains a temperature of said arrayed waveguide grating constant in order to determine the reference wavelength;each of said locking amplifiers and a corresponding one of said proportional/integration/differentiating units compute a bias current corresponding to the incoming signal; andeach of said superposing units superposes the bias current and a signal from an associated one of said signal generators and outputs a superposed signal to a corresponding one of said laser diode drivers.