They are constructed by fusing and tapering two fibers together. Typical excess losses are as low as 0. 2dB, while splitting ratios are accurate to within ±5 percent at the design. Fused couplers are used to split optical signals between two fibers, or to combine optical signals from two fibers into one fiber. A coupler can be used as a splitter to couple out some portion of the light circulating in the resonator of fiber laser, for example. The same kind of device is useful in fiber interferometers, also for combining two. The most common splitter designs use either fused biconical taper (FBT) or planar lightwave circuit (PLC) technology, each with unique ways to split light: Fused Biconical Taper (FBT): Process: Multiple fibers are twisted together, heated, and stretched to create a tapered region where their cores. There are two main types of fiber splitters: fused fiber splitters and PLC (Planar Lightwave Circuit) splitters. Arrangements of mirrors or prisms used as camera attachments to photograph stereoscopic image pairs with one lens and one exposure are sometimes called "beam splitters", but that is a misnomer, as they are.
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