Introduction to popular science about optical isolators

An optical isolator is a passive optical device that only allows one-way light to pass through. Its working principle is based on the non-reciprocity of Faraday rotation. The light reflected by the optical fiber echo can be well isolated by the optical isolator.

Optical isolators mainly use the Faraday effect of magneto-optical crystals. The characteristics of the optical isolator are: low forward insertion loss, high reverse isolation, and high return loss. An optical isolator is a passive device that allows light to pass in one direction but prevents it from passing in the opposite direction. Its function is to limit the direction of light so that light can only be transmitted in one direction. The light reflected by the optical fiber echo can be reflected by the optical isolator. Good isolation, improve light wave transmission efficiency

It is also a dual-port optical device with non-reciprocal characteristics. It attenuates the optical signal transmitted in the forward direction very little and greatly attenuates the optical signal transmitted in the opposite direction, forming a one-way path of light. Connecting an optical isolator between the laser and the transmission fiber can effectively suppress the reflected light generated from the distal end of the fiber and the interface of the fiber connector in the line from returning to the laser, thereby ensuring the stability of the laser working state and reducing the system caused by reflected light Noise. This is more important for high-speed optical fiber communication coherent optical fiber communication system.