Working principle of optical splitter
Optical splitter is a core passive device in FTTH system. Optical splitter, also known as optical beam splitter, is an integrated waveguide optical power distribution device, which can divide an input optical signal into two or more output optical signals, and the optical input power is evenly distributed on all output ports. For example, an optical splitter with a 1:4 split ratio can divide an optical signal into four equal parts and then transmit it in four different channels. At present, the splitting ratio of optical splitters is generally 1: N or 2: N, such as 1:4, 1:8, 1:16, 1:32, 2:16, 2:32.
The working principle of optical splitter is as follows: When the single-mode fiber transmits the optical signal, the energy of the light is not completely concentrated in the fiber core, but a small amount is propagated through the cladding close to the fiber core. That is to say, if the fiber cores of the two fibers are close enough, the mode field of the light transmitted in one fiber can enter the other fiber, and the optical signal is redistributed in the two fibers.
Optical splitter
Classification of optical splitters
According to the different optical splitting principle and manufacturing process, optical splitters can be divided into melting pull cone type (FBT) and plane waveguide type (PLC).
PLC optical splitter
PLC Splitter is an integrated waveguide optical power distribution device based on quartz substrate. Its main function is to divide optical signals from one optical fiber into several optical fibers. The device is coupled by an optical splitter chip and an optical fiber array at both ends. The chip is the core component, and the quality of the chip and the splitter channel directly affect the price of the whole splitter. The chip has an input end and N output waveguides. The fiber array is located on the upper surface of the chip, seals the shell, and forms an optical splitter with one input and N output fibers.
PLC optical splitter
Fused pull cone (FBT) optical splitter
Melt drawing technology is to bundle two or more optical fibers that have been removed from the coating layer together, and then melt and stretch in the drawing machine, and monitor the change of the spectral ratio in real time, and end the melting and stretch after the spectral ratio reaches the requirements, one end of which retains an optical fiber (the rest is cut off) as the input end, the other end is used as the multi-channel output end.
Fused pull cone (FBT) optical splitter
