QSFP-DD

The Technologies of Next-Generation Optical Transceivers – PAM4 and 64QAM

The shift to cloud services and virtualized networks has put the data center in the middle of our world and meant that connectivity within data centers and between data centers has a huge impact on the delivery of business and personal services. Hyperscale data centers are being installed across the world and these all need connecting. To meet this demand,…

What is PAM4 technology

PAM4 — The High-Speed Signal Interconnection Technology of Next-Generation Data Center

What Is PAM4? PAM4 (4-Level Pulse Amplitude Modulation) is one of PAM modulation technologies that uses 4 different signal levels for signal transmission. Each symbol period can represent 2 bits of logic information (0, 1, 2, 3), that is, four levels per unit time. In the data center and short-distance optical fiber transmission, the modulation scheme of NRZ is still…

working principle of 50GE PAM4 optical module

What is PAM4 Encoding Technology?

With the PAM4 encoding technology, the amount of information transmitted on 50G PAM4-based optical transceivers within each sampling cycle doubles. A 25G optical component can be used to achieve a 50Gbps transmission rate, reducing the costs of optical transceivers. 50G PAM4 applies to multiple scenarios, such as single-lane 50GE PAM4 optical transceivers, 4-lane 200GE optical transceivers, and 8-lane 400GE optical…

Which Is Better for 80km Links? PAM4 or Coherent Technology

A significant portion of Data Center Interconnections (DCIs) and telecom router-to-router interconnections rely on simple ZR or 80km transceivers. The former is mostly based on 100Gbps per 100GHz ITU-T window C-band DWDM transceivers, while the latter is mostly 10G or 100G grey wavelength transceivers. In DWDM links, the laser wavelength is fixed to a specified grid, so that with DWDM…