A duplex fiber-optic connector connects to two optical ports, whereas a simplex connector connects to a single optical port. A duplex connector is often used with a dual fiber transceiver.
You can use two simplex fiber-optic patch cables in place of a single duplex cable and vice versa.
A single simplex fiber-optic cable provides a single direction of communication when used with a dual fiber transceiver. However, you can also use a single simplex fiber-optic cable for bi-directional communication via a single fiber (BiDi) transceiver. A duplex fiber-optic cable allows for bi-directional communication by using a pair of fiber strands.
Kevin Jones / TechReviewer
The primary benefit of a duplex connector is convenience. It prevents you from mixing up which cable goes to a dual fiber transceiver's transmit or receive port.
Simplex connectors and cables are useful for single fiber (BiDi) transceivers, which transmit and receive using a single fiber optic cable.
Simplex connectors also allow for more flexibility in making connections. For example, suppose you had an MTP to LC breakout cable, which fanned out to multiple LC connectors. By using individual simplex cables, you would be able to easily re-order or replace individual connections.
A less common use case for a simplex connector is for one-way communication when there's no need to both send and receive data.
A duplex and simplex cable are interchangeable in terms of compatibility. However, we'd recommend using a duplex connector for dual fiber transceiver and simplex connectors for a single fiber (BiDi) transceiver.
There are currently not very many pre-made simplex multi-mode fiber cables available on the market. Simplex single-mode fiber cables seem to be more widely available.
- LC-LC Multi-mode fiber
- LC to LC OM3 MMF duplex fiber patch cable Fiber Patch Cable - LC to LC OM3 10Gb/Gigabit Multi-Mode Duplex 50/125 Check Price on Amazon (affiliate link)
- LC-LC Single-mode fiber
- SC-SC Multi-mode fiber
- SC to SC OM3 MMF duplex fiber patch cable Fiber Patch Cable - SC to SC OM3 Multi-Mode Duplex 50/125 Check Price on Amazon (affiliate link)
- SC-SC Single-mode fiber
Learn more about fiber optic terms and components in my article on setting up a fiber-optic network in your home or office.