SLQSDD-400G-SR4B is a parallel 400Gb/s Quad Small Form Factor Pluggable--double density (QSFP-DD) Bi-Direction optical module. The module accepts eight host electrical data and transmits them in two groups of optical bi-directional lanes (each group contains 4 pairs of optical lane) to allow optical communication over optical multi-mode fibers. Reversely, on the receiver side, the module accepts 8 sets of optical input signal and converts them to 8 channels of electrical data.

An optical fiber cable with an MPO-12 connector can be plugged into the QSFP-DD SR4 module receptacle. Proper alignment is ensured by the guide pins inside the receptacle. The cable usually cannot be twisted for proper channel to channel alignment. Electrical connection is achieved through an MSA compliant 76-pin edge type connector.

This product is allowed for two typical applications: The first application is QSFP-DD SR4.2 to QSFPDD SR4.2 point to point communication. The second application is QSFP-DD SR4.2 to 4x QSFP28 SR1.2 breakout communication.

The product is designed with form factor, optical/electrical connection and digital diagnostic interface according to the QSFP28 Multi-Source Agreement (MSA). It has been designed to meet the harshest external operating conditions including temperature, humidity and EMI interference. The module offers very high functionality and feature integration, accessible via a two-wire serial interface.