Optical fiber splitter is a device used to split and combine light wave energy. It distributes the light energy transmitted in an optical fiber to two or more optical fibers according to a predetermined ratio, or combines the light energy transmitted in multiple optical fibers into one optical fiber. Optical fiber splitters are widely used in optical fiber communication systems, radio and television networks and other fields.
When a single-mode fiber conducts an optical signal, the energy of the light is not completely concentrated in the core and propagated in a small amount through the cladding close to the core. In other words, if the cores of the two optical fibers are close enough, the mode field of the light transmitted in one optical fiber can enter the other optical fiber, and the optical signal is redistributed in the two optical fibers.
According to the principle, the optical splitter can be divided into a Fused Bi-conical Tap (FBT) and a Planar Light wave Circuit (PLC). Two types, FBT products are made by fusion splicing two or more optical fibers on the side; PLC is a micro-optical component type product, which uses photolithography technology to form optical waveguides on a dielectric or semiconductor substrate to achieve branch distribution features. The two types of optical splitting principles are similar. They achieve different branch amounts by changing the evanescent field coupling between the fibers (coupling degree, coupling length) and changing the fiber radius. On the contrary, multiple optical signals can be combined into one signal. It’s called a synthesizer. The fusion-tapered fiber optic coupler has become the mainstream manufacturing technology in the market because of its simple manufacturing method, low price, easy connection with external optical fibers, and resistance to mechanical vibration and temperature changes.
Pros and cons
FBT separator can provide low-cost common materials (quartz substrate, stainless steel, fiber, thermal dormitory, GEL) and adjustable separation ratio. However, its loss is related to the wavelength, its spectral uniformity is poor, it cannot ensure a uniform spectrum, and it is sensitive to temperature.
PLC splitter: Loss is not sensitive to wavelength, with higher spectral uniformity, more compactness, higher resolution, and lower cost. However, the device manufacturing process is more complicated.
Post time: 2021-01-18