In the field of optical communication, the packaging of optical devices plays a crucial role in the performance and application of optical modules. Selection 2: Optical chip types: VCSEL, DFB, EML, narrow linewidth tunable. Each option is directly related to certain performance requirements of the product and is strongly correlated with the final product's reliability, cost, and other factors. This meticulous process ensures light-speed data transmission with minimal loss. Today, we will discuss the differences. These technologies use either “Edge Emitting Laser (EEL) + Single-Mode Fiber” or “Vertical Cavity Surface Emitting Laser (VCSEL) +Multi-Mode Fiber”.