Single-mode four-fiber transceiver

A single-mode four-fiber transceiver (PSM4) is a parallel optical module that uses four fibers for transmitting and four fibers for receiving, enabling cost-effective 100 Gb/s data transmission over single-mode fiber for short to medium distances.

Overview

A single-mode four-fiber transceiver, commonly referred to as PSM4 (Parallel Single Mode 4-channel), is designed to transmit high-speed data over single-mode fiber using a parallel fiber architecture. Unlike traditional duplex single-mode transceivers, PSM4 splits a single laser source into four separate channels, each modulated with electrical data signals, and transmits them simultaneously over four fibers. The receiving end uses four fibers to capture the signals, allowing bidirectional communication at high speeds (up to 100 Gb/s) with low signal loss and minimal interference (NVIDIA Enterprise Support Portal), .

Fiber Configuration

• Transmission fibers: 4 fibers dedicated to sending data
• Receiving fibers: 4 fibers dedicated to receiving data
• Connector type: Typically uses an 8-fiber MPO (Multiple Push-On) connector for parallel alignment
• Advantages: Parallel transmission reduces cost per bit and simplifies high-speed data transfer in data centers (NVIDIA Enterprise Support Portal), .

Applications

• Data centers: Ideal for short-reach interconnects, typically up to 2 km, with optimal performance under 500 meters
• Enterprise networks: Campus backbone links and high-density switch uplinks
• Telecom networks: Metro networks requiring high bandwidth over single-mode fiber
• Comparison with duplex single-mode: For longer distances, duplex single-mode transceivers using CWDM4 (two fibers) may be more economical due to reduced fiber count (NVIDIA Enterprise Support Portal), .

Technical Specifications

• Wavelengths: Usually 1310 nm or 1550 nm for single-mode operation
• Fiber core: 9/125 µm single-mode fiber
• Data rate: 100 Gb/s (aggregated across four channels)
• Distance: Up to 2 km, depending on optical power budget and link quality
• Hot-swappable: Can be replaced without powering down network equipment (L-P.com),

Benefits

• High bandwidth: Supports 100 Gb/s over single-mode fiber
• Cost-effective: Uses a single laser split into four channels, reducing component cost
• Scalable: Suitable for high-density switch ports and modular network expansion
• Low interference: Single-mode fiber ensures minimal signal attenuation and EMI/RFI immunity (SEL-2830),

Summary

Single-mode four-fiber transceivers (PSM4) are a practical solution for high-speed, short- to medium-range optical links in modern data centers and enterprise networks. They combine the advantages of single-mode fiber—longer reach and low attenuation—with parallel transmission to achieve 100 Gb/s performance efficiently. For longer distances or cost-sensitive deployments, duplex single-mode transceivers with CWDM4 may be preferred. These modules are hot-swappable, scalable, and ideal for backbone and uplink connections (Fiber24, L-P.com, NVIDIA Enterprise Support Portal), .