What is a Fiber Array?

Fiber Array (FA for short) is an array formed by installing a bundle of optical fibers or a fiber ribbon on the substrate at specified intervals by using a V-Groove (V-Groove) substrate.

The optical fiber array in optical communication mainly includes a substrate, a pressing plate, and an optical fiber. Usually, a plurality of grooves are cut in the base of the substrate, and the pressure plate is pressed and the optical fiber inserted into the groove is fixed. The fiber array has very high requirements on materials and manufacturing processes.

1. How to realize positioning of optical fiber array?

The optical fiber array mainly relies on precision engraved V-shaped grooves to achieve positioning. The V-groove needs to use a special cutting process to achieve precise fiber positioning. The bare fiber part with the fiber coating removed is placed in the V-groove. This process requires ultra-precision processing technology to accurately position the fiber core in the V-groove to reduce the connection loss. And then press the parts by the pressurizer and fix with an adhesive, and optically polish the end face to form an optical fiber v-groove array.

The substrate material will affect the optical properties of the optical fiber array. It is necessary to use a material with a small expansion coefficient to ensure that the optical fiber array is stress-free, high reliability, and no fiber displacement at high temperatures. Glass and silicon are commonly used materials, in addition to ceramics, there are conductive substrates and plastic substrates.

The distance between the grooves of the V-shaped groove, the number of fiber channels, and the grinding angle are all customized according to the needs, but the accuracy of the center-to-center dimension between the adjacent grooves is ±0.5μm, and the parallelism of the groove length direction between the adjacent grooves is within ±0.1 degrees. The optical fibers used in the optical fiber array are mostly colored ribbon fibers, which have good bending resistance, and the colorful colors can easily distinguish the channels.

2. Application of optical fiber array

Fiber arrays are usually used in planar optical waveguides, arrayed waveguide gratings, active/passive array fiber devices, micro-electromechanical systems, multi-channel optical modules, etc. Among them, the optical fiber array is one of the important components of the fiber optic PLC splitter, which can greatly reduce the loss of the optical waveguide device and the optical coupling alignment.