Fiber Array (FA) is an array consisting of a bundle of optical fibers or a ribbon of optical fibers mounted on a substrate at specified intervals using a V-Groove substrate.
Fiber optic arrays in optical communications mainly include a substrate, a platen, and an optical fiber.
Usually, multiple grooves are cut in the base of the substrate, and the platen presses and fixes the optical fiber inserted into the grooves.
Therefore, fiber optic arrays have very high requirements for materials and manufacturing processes.
Fiber optic arrays rely primarily on precision-engraved V-grooves for positioning.
The V-groove requires a special cutting process to achieve precise fiber positioning, the bare fiber without coating is placed in the V-groove, the process requires ultra-precision machining technology to accurately locate the fiber core within the V-groove in order to reduce the connection loss, and then pressurised by the pressurised components and fixed with adhesive, the end faces are optically ground to form the fiber array.
The substrate material affects the optical properties of the fiber array, and a material with a low coefficient of expansion is required to ensure stress-free, highly reliable fiber arrays and no fiber migration at high temperatures.
Glass and silicon are commonly used, but ceramics, conductive substrates and plastic substrates are also available.
The groove-to-groove distance, the number of optical fiber channels, and the grinding angle of the V-groove are customized according to demand, but the centre-to-centre dimensions between adjacent grooves to each other have an accuracy of ± 0.5 μm, and the parallelism in the direction of the groove length between adjacent grooves is within ± 0.1 degree.
Most of the optical fibers used in FA are coloured ribbon fibers with good bending resistance, and the colourful colours make it easy to differentiate the channels.
Fiber arrays are commonly used in planar optical waveguides, arrayed waveguide gratings, active/passive arrayed fiber optic devices, microelectromechanical systems, multi-channel optical modules, and optical splitters.
Among them, the optical fiber array is one of the important components of planar light waveguide splitter (PLC Splitter), which can greatly reduce the loss of optical waveguide devices and optical coupling alignment.