Learn how optocouplers ensure electrical isolation and signal transfer in circuits. This guide covers their components, working principles, and applications. Optocouplers are very useful when you need to isolate different sections of a circuit, for example in power. Optocouplers, also known as opto-isolators or photocouplers, are electronic components that transfer signals between two isolated circuits using light. Mouser is an authorized distributor for many optocoupler manufacturers including Broadcom, onsemi, Renesas, Toshiba, Vishay & more.