Surface-mount-technology (SMT) has been widely used in electronics board assembling. Compared to the throughhole mounted device surface mount devices (SMD) have a number of advantages such as smaller size, higher degree of assembling automation, and higher circuit density. Components can be mounted on both sides of the board. They are more robust under mechanical stress and have a lower lead resistance and inductance leading to better performance for high frequencies. Adopting SMT in opto-electronic packaging is very attractive not only due to the advantages of receive part of the optical output and feedback the photocurrent into the laser diode driver. The laser diode driver controls the bias current to the VCSEL automatically to stabilize the optical output power. Besides, a barrel feature is integrated with a lens in the module housing to facilitate an easy and robust coupling to the external optical cable. Figure 4 shows the schematic diagram of the transmitter module with the optical feedback loop and coupling optics.