What’s Polarization Maintaining(PM) fiber connector?

Polarization maintaining(PM) optical fiber connectors are often employed for special applications, for example optical fiber sensing, interferometry, planar waveguides, coherent optical transmission, and lengthy-distance bidirectional optical transmission systems. To know polarization-maintaining connectors, we have to understand what polarization-maintaining fibers are.

The PM fibers presently available on the market essentially possess the following mix-sectional types:

The mix-sectional kinds of PM fibers

The 5th is easily the most common type, which also referred to as Panda fiber (Its mix-section appears like a panda face). What’s the main difference between PM fiber and ordinary single-mode fiber?

Polarization-maintaining fiber is really a special kind of single-mode fiber. Ordinary single-mode fiber can transmit random polarized light, while PM fiber are only able to transmit polarized light one way. In polarization-maintaining fibers, the polarization of linearly polarized light waves propagating in to the fiber is maintained throughout the propagation process, and there’s little if any mix-coupling of optical power between your polarization planes. For many fiber components that need polarized light input (for example exterior modulators), the part of maintaining the polarization direction is essential. By generating stress within the fiber material itself, the polarization characteristics of sunshine waves inside a specific direction could be maintained. Therefore, the polarization maintaining fiber using the following structure seems.

Structure of PM fiber optic connector

The strain fishing rod generates stress within the optical fiber, which only plays a role in the polarization propagation of sunshine one way. Once the PM fiber is ended with the fiber connector, the strain fishing rod ought to be aligned using the connector key. If the keys are aligned directly determines the part from the PM connector link transmission. The index is extremely critical.

How to make sure that the strain fishing rod and connector key are aligned? To ensure accurate alignment, do we have to perform some special the perception of the dwelling from the connector?

The strain fishing rod ought to be aligned using the connector key. The traditional production method available on the market would be to fill the ferrule with 353ND curing glue. Once the glue isn’t fixed, align the strain fishing rod (cat’s eye) using the magnifier by rotating the lens core, after which cure after alignment. However , the fiber core is extremely simple to rotate throughout the baking process despite aligning the “cat’s eye”. And there’s a particular viscosity from the cured glue, which in turn causes the fiber core to rotate offset after alignment and before curing. The alignment position from the “cat’s eye” are only able to achieve within ± 5 levels, and also the extinction ratio from the entire jumper are only able to achieve greater than 20dB. And when the offset position is simply too large, the connector finish should be stop and re-headed, wasting man-hrs and also the quality is tough to ensure.

HYC PM connector

To be able to solve the above mentioned problems, HYC has individually developed a polarization maintaining fiber connector that may rotate the ferrule with all over position to align using the “cat’s eye”. The standard rotating optical fiber core is substituted with rotating the solidified ferrule. Once the “cat’s eyes” are aligned, the ferrule tail is bound to offer the reason for precise positioning. After verification, the alignment position deviation of HYC series polarization-maintaining connectors could be controlled within ±1 degree , and also the extinction ratio can achieve greater than 25dB.

By Harris