Knowledge About the Origin of Polarization Retaining Fiber Coupler

1. What is a polarization-maintaining fiber coupler?

Polarization-maintaining coupler is a device for detachable (movable) connection between fiber and fiber. It precisely connects the two end faces of the fibers so that the light energy output by the transmitting fiber can be coupled to the receiving fiber to the maximum extent. And make it intervene in the optical link to reduce the impact on the system.

For a waveguide coupler, it is generally an element with a Y-branch, and the optical signal input by an fiber can be divided into equal parts. When the opening angle of  the polarization-maintaining coupler increases, the amount of light leaking into the cladding will increase, which will increase the excess loss. Therefore, the opening angle is generally within 30°, so the length of the waveguide Polarization-maintaining fiber coupler should not be too short.

2. Features and applications of polarization-maintaining fiber couplers

The polarization-maintaining fiber coupler is prepared by a unique fusion tapering process, used for light splitting in the optical path, and can equally divide the input light into three beams.

The polarization-maintaining coupler has passed a variety of reliability tests and various military environmental assessment tests, with stable performance and high reliability, and has been applied in many key national projects.

The main features of the polarization-maintaining coupler: small size, low additional loss, good environmental stability, and high reliability.

Polarization-maintaining couplers can be mainly used in: coherent optical communications, fiber optic gyroscopes and fiber optic sensors.

Since the optical network system also needs to couple, branch, and distribute optical signals, this requires an fiber coupler. Fiber coupler, also known as optical splitter and splitter, is one of the important passive components in the optical fiber link. It is an optical fiber tandem device with multiple input ends and multiple output ends. M×N is often used to represent a splitter. The router has M input terminals and N output terminals.