SEMICONDUCTOR LASER AND DRIVE METHOD THEREFOR, OPTICAL COMMUNICATION METHOD AND NODE, AND OPTICAL COMMUNICATION SYSTEM

摘要

PURPOSE: To realize transmission with higher density by injecting a main modulation current into a part of a plurality of electrodes, while simultaneously, injecting a submodulation current having a phase regulated with respect to the main modulation current to the remaining electrodes at the time of low frequency switching. CONSTITUTION: An electrode 109 is fed not with a main modulation currentΔI1 but with a submodulation currentΔI2 . The oscillation mode of TE/TM is distributed such that when a DC bias is fixed in the vicinity of the switching point of a polarized wave, the polarized wave is switched from TE to TM upon increase of I1 and from TM to TE upon increase of I2 Consequently, the switching phase for the variation of I1 and I2 is reversed. When a modulation currentΔI1 in-phase with theΔI2 is fed, the switching direction of polarized wave due to heat is reversed as compared with theΔI1 and thereby switching of polarized wave can be suppressed for theΔI1 . This structure realizes high density transmission.