Structural composition of SFP optical module

The optical module is a very important active device in the optical communication transmission system. It is a photoelectric module for photoelectric and electro-optical conversion. It can play the role of photoelectric signal conversion in optical communication. With the rapid development of the telecommunications market and the data communication market. The data transmission requirements of optical communication services are also greatly improved. In order to adapt to the rapid development of the market, optical modules are also evolving. Miniaturization, high-speed, low-power optical modules are the future development trend.

Hot-swappable small package module in SFP compact package. Its main function is to convert the electrical signal at the transmitting end into an optical signal and transmit it out. After receiving the information, the receiving end restores the optical signal to an electrical signal.

The compact optical module is mainly composed of laser (including transmitter TOSA and receiver ROSA), circuit board IC and external accessories. The external accessories are composed of shell, base, PCBA, pull ring, buckle, unlocking piece, and rubber plug.

In terms of key functions, compact optical modules are mainly composed of TOSA components, ROSA components and PCBA boards. The launching component TOSA is the main part of the light launching module. Among them, the light source laser diode is the core, and the LD chip and the monitoring photodiode (MD) plus other components are packaged in the TO coaxial to form the light emitting component TOSA. The function of the receiving component ROSA is to convert the weak light signal after transmission into an electrical signal. And amplify and reshape to restore the original input electrical signal. The photodetector and the pre-(transimpedance) amplifier plus other components are packaged in a compact structure to form the receiving component ROSA. Commonly used ROSAs are PIN-TIA and APD-TIA. PCBA board, PCBA is composed of light transmitting circuit and receiving circuit. The main chips are driver chips, limiting amplifiers, and storage chips. 

The above is the part of the SFP optical module. Although the composition and structure seem to be simple, in fact the technical content is very high. Especially for chip manufacturing technology, currently only chips with medium and low-end transmission rates are manufactured in China. For chips with high transmission rates, it can only rely on imports. Major domestic chip manufacturers are also increasing their research and development efforts. It is believed that in the near future, domestic chips can completely replace imported chips, realizing completely independent production and manufacturing of optical modules.