An optical isolator is a passive device that allows light to pass in one direction and prevents light from passing in the opposite direction. Its function is to limit the direction of light, so that light can only be transmitted in single direction. The light reflected through optical fiber echo can be well isolated by the optical isolator, improving the transmission efficiency of light wave.

Features of Optical Isolators

- High isolation
- High return loss
- High reliability
- High stability
- Low insertion loss
- Low Polarization Dependent Loss
- Low Polarization Mode Dispersion

Functions of Optical Isolators

The function of optical isolator is to prevent the bad influence of the backward-transmitted light on the light source and the optical system caused by various reasons.

For example, by installing an optical isolator between semiconductor laser source and optical transmission system will greatly reduce the adverse effect of reflected light on the stability of the spectral output power of the light source. In high-speed direct modulation and direct detection optical fiber communication system, additional noise will be generated by backward transmission of light, degrading the system performance, which needs optical isolator to eliminate. Installing optical isolators at both ends of doped fiber in fiber amplifier can improve the working stability of fiber amplifier. Without optical isolator, backward-reflected light will enter the signal source (laser), causing violent fluctuations in the signal source. The power loss caused by Brillouin scattering can be reduced by installing optical isolators at intervals in coherent optical long distance optical fiber communication systems. Therefore, optical isolators play an important role in optical fiber communication, optical information processing system, optical fiber sensing and precision optical measurement system.