What are the core components of the optical module?

1. TOSA: It is mainly used to convert electrical signals into optical signals, mainly including laser, MPD, TEC, isolator, Mux, coupling lens and other devices, including TO-CAN, Gold BOX, COC (chip on chip), COB (chip on board) and other packaging forms. For the optical modules applied in the data center, TEC, MPD and isolator are not necessary items to save costs.

Mux is also only used in optical modules requiring wavelength division multiplexing. In addition, LDDs of some optical modules are also packaged in TOSA. In the chip manufacturing process, the epitaxial wafer is made into a laser diode. Then, the laser diode, together with filter, metal cover and other components, is packaged into a TO can (Transmitter Outline can), and then the TO can and ceramic sleeve and other components are packaged into an optical sub module (OSA), and finally the electronic sub module.

2. LDD (LaserDiode Driver): convert the CDR output signal into corresponding modulation signal to drive the laser to emit light. Different types of LDD chips need to be selected for different types of lasers. In short-range multimode optical modules (such as 100G SR4), CDR and LDD are generally integrated on the same chip.