Electromagnetic Optimization of High-speed TO Laser Modules

The packaging aspect of the high-speed TO laser module has been investigated in this paper. A conventional TO 56 package is employed for compact and low cost high-speed applications. In the TO header, a special designed RF substrate is developed to minimize the RF reflection and insert loss. The influence of the feedthrough and the TO leads on signal transmission is analyzed using the electromagnetic (EM) method. A testing interface PCB based on the tapered coplanar waveguide (CPW) transmission line is proposed, and simulation results indicate that the coaxial type TO package has an insert loss of 1.5dB at 10GHz. In order to improve the electronic performance of the TO module, the equivalent circuit is built and a bandwidth compensation circuit is introduced, and results show that the 3dB bandwidth of the TO package can extend to 16.3GHz.