As data centers and telecom operators have higher and higher requirements for the transmission rate of optical modules, what technologies do optical module manufacturers use to achieve higher transmission rate? This article will reveal the answer for you.

1. Increase the baud rate, which refers to the modulation rate of the data signal to the carrier. This method is mostly used in low-speed optical modules, such as 10g, but when it is increased to a higher rate, the signal-to-noise ratio becomes a difficult problem to solve.

2. The multi-channel parallel transmission technology is used. The technology uses four channels of the same wavelength for transmission. The main working wavelengths are 850 and 1310nm. The main representative optical modules are 40g and 100g Sr4 / psm4.

3. Using wavelength division multiplexing technology to improve transmission rate

(1) LAN WDM fine wavelength division multiplexing uses 12 wavelengths in the 1269nm to 1332nm band in the o-band (1260nm ~ 1360nm) range, with a wavelength interval of 4nm. The optical modules adopting this technology include 100g LR4 / Er4 / Zr4, and their working wavelengths are 1295, 1300, 1304 and 1309 nm。

(2) CWDM coarse wavelength division multiplexing technology, represented by optical modules 100g cwdm4, 100g Clr4, etc.

(3) Swdm short wave division multiplexing technology has a wavelength range of 850-950nm and a band interval of 30nm, which are 850, 880, 910 and 940nm respectively. The representative optical modules include multimode 40g swdm4 and 100g swdm4.

4. Pulse amplitude modulation (pam4) is used to carry 4 times the amount of data in the same time period instead of non return to zero modulation (NRZ) to achieve higher data rate. Whether NRZ or pam4 is used, some forward error correction (FEC) algorithm is required. Because the interference signal has a great impact on pam4, a more complex FEC algorithm is needed. The representative optical modules are 50g sfp56 Sr, 200g qsfp56 FR4 (4 * 53gb / s pam4), 400g qsfp-dd SR8 (8 * 53gb / s pam4).

As people have higher and higher requirements for network speed, you may lose a large number of customers due to the slow opening speed of the website and the slow corresponding speed of the server. Therefore, it is very necessary to improve the transmission rate of network devices.

Statement: This article comes from the Internet