Design And Fabrication Of A Novel Complex-Coupled Mqw-Dfb Laser By Way Of Modulated Distribution Of Injection Current

A kind of novel complex-coupled gratings by modulated distribution of injection current (MDIC) along the propagating direction of modes of lasers, was designed and analyzed theoretically. The impacts of two practical cases on MDIC gratings were discussed, which indicated the MDIC gratings could function effectively. Some necessary parameters were calculated and were put into practice in actual device process successfully and proved to be reliable. Furthermore, MDIC DFB lasers, based on the active layer with five quantum wells, were fabricated firstly by MOCVD and LPE. The devices began to lase continually about 30mA. The stable single longitudinal mode wavelength is just at 1.3151 ��m, located in the zero dispersion window of optical fibers. There is no appearance of stop band in the quasi-threshold spectrum. As a consequence, high side mode suppression ratio of more than 30dB and high single longitudinal mode yield have been realized by using this MDIC complex-coupled structure.