halbleiterlaser, modulation method and optical communication system

摘要

A semiconductor laser of the present invention includes a semiconductor laser structure having a waveguide extending along a resonance direction, an active layer (32, 132, 232, 332, 432, 532, 632, 732, 832) provided at least partly in the waveguide, and a control unit (19a, 19b, 20; 119a, 119b, 119c, 120; 219a, 219b, 219c, 220; 319a, 319b, 320; 419a, 419b, 419c, 420; 519a, 519b, 519c, 520; 619a, 619b, 620; 719a, 719b, 719c, 720; 819a, 819b, 819c, 820) for controlling the excited state of the semiconductor laser structure to change the relationship between wavelengths or propagation constants and threshold gains for transverse electric (TE) mode and transverse magnetic (TM) mode of the laser structure. The waveguide is designed such that threshold gains for the TE mode and the TM mode can be alternately made minimum under the control of the control unit. IMAGE