What is QSFP-40G-SR4?
The package type of QSFP-40G-SR4 optical module is QSFP+ (Quad Small Form-factor Pluggable Plus). When used with OM3 fiber patch cords, the transmission distance can reach up to 100 meters; when used with OM4 fiber patch cords, transmission The distance can be up to 150 meters. QSFP-40G-SR4 optical module can not only realize 40G transmission by connecting 12-core MTP/MPO fiber jumper, but also realize 4x10G transmission by connecting 8-core MTP-LC branch cable.
What's the difference between 40G QSFP+ SR4 vs BiDi optical module?
Although both QSFP-40G-SR4 and QSFP-40G-SR-BD optical modules can be used with multi-mode patch cords, the longest transmission distance can reach 150 meters. But the difference between these two optical modules is also obvious: QSFP-40G-SR4 optical module is MTP interface, while QSFP-40G-SR-BD optical module is LC interface, and only the former can realize 4x10G connection.
QSFP-40G-SR4 optical module working principle
QSFP-40G-SR4 optical module is mainly used for 40G data rate optical transmission. There are 4 independent optical signal transmitting and receiving channels inside, each channel can support 10Gbps data transmission. QSFP-40G-SR4 optical modules are often used with 12-core MTP trunk fiber jumpers, 4 cores are used for transmitting, 4 cores are used for receiving, and the middle 4 cores are idle.
QSFP-40G-SR-BD optical module working principle
The QSFP-40G-SR-BD optical module is different from the above-mentioned optical module. It combines 4 10Gbps signal channels into 2 two-way transmission 20Gbps signal channels. Each transceiver channel simultaneously transmits and receives optical signals from different wavelengths (usually 850nm/900nm) on a multimode fiber. QSFP-40G-SR-BD optical modules are often used with duplex LC fiber jumpers, so 40G transmission can be achieved without changing the existing 10G wiring pattern.
