Optical transceiver is usually composed of an optical transmitting module (including a laser), an optical receiving module (including a light detector), a driving circuit and an optical and electrical interface, etc., which is used to realize the conversion of electric-optical and optic-electrical signals. At the sending end, the electric signal at a certain rate is processed by the driver chip and then the laser is driven to emit the modulated optical signal at the corresponding rate. Through the optical power automatic control circuit, the optical signal with stable power is output. At the receiving end, the optical signal of a certain rate is input into the transceiver and converted into electrical signal by the optical detector, and the electrical signal of the corresponding rate is output after the preamplifier.
Among them, optical and electrical chips are the most important devices, and optical chips account for the highest cost. For 10G low-rate optical transceiver, the cost of optical chips accounts for about 30%, while for high-rate optical transceiver greater than 25G, the cost of optical chips accounts for more than 50%, and more than 60% for 400G optical transceiver. The optical and electric chips are the core components of the optical transceiver. The transmission rate of the optical chip determines the transmission rate of the optical transceiver, while the electric chip is responsible for the amplification and processing of the signals in the optical transceiver. The technology threshold of optical and electric chips used in optical transceiver is very high. At present, the mainstream manufacturers of optical chips are still mainly concentrated in the United States, and optical chip manufacturers are relatively concentrated. Although there are more electric chip manufacturers, the concentration of each segment field is also high. And China is still subject to others in the chip field, restricting the development of optical transceiver industry.
The transmission rate of the optical chip directly determines the transmission rate of the optical transceiver. The 100Gb/s optical module can be integrated by four 25Gb/s optical chips. Therefore, the higher the transmission rate of the optical chip itself, the higher the transmission rate of the integrated optical transceiver. Chinese optical chip industry is still in its infancy, lagging behind developed countries by about three years in the research and development process of high-speed chips (25Gb/s and above). At present, Chinese enterprises have mass produced optical chips of 10Gb/s and below, and some 25Gb/s series chips. For optical chips above 25Gb/s, most Chinese enterprises are still in the research and development stage, so most optical transceiver enterprises still need to import optical chips produced by international advanced enterprises.
The process of optical chip is complicated, including chip design, substrate manufacturing, epitaxial growth and grain manufacturing. Chinese optical chip enterprises are all Fabless manufacturers, only responsible for the design of optical chips, substrate manufacturing, epitaxy growth, wafer manufacturing and other processes need to be outsourced to other manufacturers, optical chip industrialization is not complete, the lack of core technology and equipment is an important factor limiting the development of optical chip industry.
The localization process of electrical chips is far lower than that of optical chips, and the 25Gb/s series of electrical chips are basically dependent on imports. In the future, the target of electrical chip localization is laser driver /TIA and DSP respectively.
EXSENSE Electronics Technology Co., Ltd. has been specializes in research, development and production of optical transceiver thermal chip for 14 years, EXSENSE Electronics is committed to providing optical transceiver customers with high-quality NTC thermistor chip, to ensure the stability of operating temperature of optical transceiver.