GAIN-COUPLED DISTRIBUTED FEEDBACK SEMICONDUCTOR LASER

摘要

A gain-coupled distributed feedback semiconductor laser achieves high optical output without causing an increase in threshold current or a decrease in emission efficiency. The gain-coupled distributed feedback semiconductor laser comprises a diffraction grating at least in a portion of a resonator, and its gain or loss changes periodically. One end of the laser has a reflectivity of less than 3%, while the other end has a reflectivity of less than 60% but greater than that of the former. The gain-coupled distributed feedback semiconductor laser is of absorptive grating type, in which the resonance length is preferably 400 mu m.