Single-mode modules use a 9/125 micrometer diameter fiber optic cable and can transmit light at wavelengths of 1310nm, 1550nm with WDM. These wavelengths have longer waveforms, resulting in less fiber attenuation, and they have nearly zero absorption, making them ideal for fiber transmission. Based on the analysis of commonly used. In March, 2021, China Unicom released a series of white papers on next-generation digital infrastructure, or CUBE-Net 3. 0, and set up a demonstration base in the Guangdong–Hong Kong–Macao Greater Bay Area to promote innovation. Siemens has developed a network strategy that converges the different. Some customers want to know about the difference between multimode and single-mode SFP, so we summarize some information about multimode and single-mode optical modules.