PolarizaTIon-maintaining ("PM"), as a special application connector, is widely used in optical fiber sensing, interferometry, planar waveguide, coherent optical transmission and long-distance bidirectional optical transmission systems. To understand polarization-maintaining connectors, polarization-maintaining fibers must be used. First, you need to know what polarization-maintaining fibers are.

The most common of these is the fifth type, also known as Panda Fiber (so named "Panda Fiber" because the cross-sectional view looks like a panda's face). So what is the difference between this kind of fiber and ordinary single-mode fiber?

Polarization-maintaining fiber is a special type of single-mode fiber. Ordinary single-mode fibers can transmit randomly polarized light, while polarization-maintaining fibers can only transmit polarized light in one direction. In polarization-maintaining fibers, the polarization of linearly polarized light waves propagating into the fiber is preserved during propagation with little or no cross-coupling of optical power between polarization planes. This polarization-preserving capability is extremely important for certain fiber optic components that require polarized light input, such as external modulators. By generating stress in the fiber material itself, it is possible to maintain the property that the light wave is polarized in a specific direction, so the following structure of the polarization maintaining fiber appears. 

Stress rods create stress in the fiber, which favors light propagating polarized in only one direction. When the PM fiber is terminated through a fiber optic connector, the stress bar should align with the connector key. Whether the Key key is aligned or not directly determines the function of the PM connector link transmission, this indicator is very critical. How to ensure that the stress rod and the key of the connector are aligned? Do I need to do something special in the structure of the connector if I want to ensure accurate alignment?

The stress rod should be aligned with the key of the connector. The conventional production method on the market is to fill the ferrule with 353ND curing glue. When the glue is not fixed, align the stress rod (cat's eye) under the magnifying glass by rotating the core. Re-curing after preparation. The problem with this is that after aligning the "cat's eye", the connector needs to be moved for baking and curing, the core is very easy to rotate, and the curing glue has a certain viscosity, which causes the core to rotate after alignment and before curing. Offset, the alignment angle of the "cat's eye" can only reach within ±5 degrees, and the extinction ratio of the entire jumper can only reach more than 20dB. Moreover, once the offset angle is too large, the connector end must be cut off and reattached, which wastes man-hours and makes it difficult to guarantee the quality.

In order to solve the above problems, PUSMAI independently designed a polarization-maintaining connector that can rotate the ferrule 360 degrees to align with the "cat's eye". By rotating the cured ferrule to replace the rotating optical fiber core, when the "cat's eye" is aligned, the ferrule tail is fixed to achieve the purpose of precise positioning. After verification, the PUSMAI series polarization-maintaining connectors can control the alignment angle deviation within ±1 degree, and the extinction ratio can reach more than 25dB. 

This solution can be widely used in instruments or scenarios that are sensitive to polarization states, such as space, high radiation environments, radiation-resistant products, single-polarization transmission fields, EDFA, fiber-optic gyroscopes, fiber-optic sensing equipment, fiber-optic hydrophones, and fiber-optic currents Sensors, aerospace, navigation, unmanned systems, communications, highly sensitive interference instruments, polarization-maintaining wavelength division multiplexers and many other fields.

Shenzhen PUSMAI technology Co.,LtdIt is a manufacturer of passive optical fiber components in China integrating R&D, production, sales and after-sales. Currently, it mainly focuses on polarization-maintaining optical fiber components and high-power optical fiber components in the 405nm~2050mm band, PUSMAI product PM/High power optic circulator , PM/High power optic isolator , PM/High power optic patch cord  , PM/High power optic optic swith and also provides customers with TP-PD, LD laser products. Solutions and customized services.