As data centers and telecom operators require higher transmission rates for optical modules, what technologies do optical module manufacturers use to achieve higher transmission rates? This article ETU-LINK will reveal the answer for you.

1. Increase the baud rate. The baud rate refers to the modulation rate of the data signal to the carrier. This method is mostly used for low rate optical modules, such as 10G. However, when increasing to a higher rate, the signal-to-noise ratio becomes a difficult problem to solve.

2. Multi channel parallel transmission technology is used. The technology uses four channels of the same wavelength for transmission. The main working wavelengths are 850 nm and 1310 nm. The main representative optical modules are 40G and 100G SR4/PSM4.

3. Using Wavelength Division Multiplexing Technology to Improve Transmission Rate

A. LAN WDM fine wavelength division multiplexing uses 12 wavelengths from 1269nm to 1332nm in the O-band (1260nm~1360nm) range, with a wavelength interval of 4nm. The optical modules using this technology include 100G LR4/ER4/ZR4, and their operating wavelengths are 1295, 1300, 1304 and 1309 nm.

B. CWDM coarse wavelength division multiplexing technology represents 100G CWDM4, 100G CLR4, etc.

C. SWDM short wavelength division multiplexing technology has a wavelength range of 850-950nm and a wavelength interval of 30nm, which are 850, 880, 910 and 940nm respectively. The representative optical modules are multimode 40G SWDM4 and 100G SWDM4.

4. Pulse amplitude modulation (PAM4) is used to carry 4 times 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, a forward error correction (FEC) algorithm is required.Because the interference signal has a great impact on PAM4, a more complex FEC algorithm is required.The representative optical modules are 50G SFP56 SR, 200G QSFP56 FR4 (4 * 53Gb/s PAM4), 400G QSFP-DD SR8 (8 * 53Gb/s PAM4).

The above are the four methods that ETU-LINK has arranged for us to improve the transmission rate of optical modules. With people's increasing requirements for network speed, you may lose a large number of customers due to the slow opening speed of websites and the slow corresponding speed of servers. Therefore, it is necessary to improve the transmission rate of network devices.