Optical isolator is a necessary passive component that widely used in fiber optic communication networks. It is used to prevent unwanted light feedback into the sensitive devices or components. As we know, light can be reflected back and forth, which will also happen in the fiber optic networks.
But the fact is most of the refection will affect the stability of the system especially for lasers. Laser is essentially a resonant cavity between two semi-transparent mirrors. The lasing process happens between these two mirrors. The lasing process is very delicate and can be easily interfered. If back-reflected and scattered light enters into the laser, the lasing process will fluctuate and the output power of the laser will fluctuate. However to prevent the bad result caused by this unwanted refection, a fiber optic isolator is needed here. A fiber optic isolator is also called optical diode, which is issued to prevent any light from reflecting back down the fiber, stopping backscattering and feedback problems on these sensitive components in the networks.
Insert loss and degree of isolation are essential features for the optic isolator. The insertion loss is mainly depend on the type and quality of the polarizers used. A high degree of isolation is generally more difficult to achieve for high-power devices, where the beam in the Faraday medium covers are larger area and is thus more sensitive to field inhomogeneities. The fiber optic isolators can be pre-installed with various kinds of fiber connectors. Ingellen offers various type of fiber optic isolator devices which features high isolation and high return loss, minimal polarization dependent loss, and very low polarization mode dispersion.
Related Reading: High Power Polarization Insensitive Isolator, Singlemode Broadband Coupler, Polarization Maintaining Faraday Mirror, Polarization Maintaining Single Fiber Collimator
