| 摘要 |
PURPOSE:To contrive the improvement of the gain being free from the polarized wave dependency, by synthesizing each output of a first optical amplifier and a second optical amplifier by an optical multiplexer to output it. CONSTITUTION:A light beam inputted to optical semiconductor laser beam amplifiers 15, 16 is always arranged so that the polarized wave direction of an input light becomes the TE polarized wave direction of the amplifier, as a polarized wave in the prescribed direction, and so that the input light receives the prescribed and maximum gain. The light beam which has been amplified by the optical amplifiers 15, 16 passes through propagation paths 17, 18 and inputted to an optical multiplexer 19. In this state, the propagation paths 17, 18 hold the polarized wave direction of the propagated light beam in the same way as propagation paths 13, 14. An optical polarized wave separating device has a function for outputting two orthogonal polarized wave light beams which have been inputted, to match one optical path, therefore, the input light beam from the propagation paths 17, 18 are synthesized and outputted to a propagation path 21 of a light beam. In such a way, a device whose gain does not depend on a polarized wave state of the input light is obtained. |
