A compact MU interface 2.5-Gb/s optical transmitter module with an embedded LD-driver IC

A compact MU interface 2.5-Gb/s optical transmitter module is described. It employs a low power consumption LD-driver IC (LD-DR) which is thermally isolated from the 1.55-μm DFB-LD attached on a TE-cooler. The optical connector interface is an MU receptacle positioned at the opposite side of the electrical miniature coaxial receptacles. The high coupling method of a DFB-LD to a single mode fiber is used. It consists of two aspheric lenses which are positioned under a confocal condition. The module using the proposed configuration has been evaluated from 10°C to 65°C. Good results of high coupling efficiency over 50%, low dissipation power less than 1.8 W (LD-DR only dissipated 0.33 W), and electrical performance at the speed of 2.5 Gb/s have been obtained with the 6.2-cc module. This compact module with low consumption will be useful for highly integrated on-board equipment required for large-capacity systems such as future SDH and WDM systems