With the recovery of optical fiber communication industry and the development of FTTX, the spring of fiber optic splitter market is coming.
There are two types of optical splitter, which are Fused fiber splitter and PLC splitter. PLC splitter is a hot research today, with a good prospect of application. PLC splitter package, however, is the difficulty in manufacturing.
The PLC splitter Package refers to the planar waveguide splitter on the light guide path (waveguide) with the fiber in the fiber array aligned one by one, and then stick with specific adhesive (such as epoxy glue) together with the technology. Wherein the alignment accuracy of the PLC splitter and an optical fiber array is the key technology. PLC splitter package involves a six-dimensional optical fiber array and optical waveguides in close alignment difficult. When the manual, the drawback is the low efficiency, poor reproducibility, human factors and is difficult to achieve large-scale production.
PLC splitter Production
PLC splitter using semiconductor technology (lithography, etching, developing technology) production. Multi-channel optical fiber array and the optical waveguide array is located on the upper surface of the chip, branching function is integrated on-chip is a chip on the splitter 1,1; Then, the ends of the chip, respectively coupling the input terminal and an output terminal package.
Compared with Fused Splitter, PLC splitter has these advantages: (1) loss wavelength is not sensitive to light, to meet the different wavelengths of the transmission needs. (2) spectroscopic uniform signal can be uniformly allocated to the user. (3) compact structure, small size, can be installed directly in the various existing junction box, without leaving a lot of space for installation. (4) only a single device shunt channel can achieve much more than 32 channels. (5) The multi-channel, low cost, stars ones more and more obvious cost advantages.
At the same time, the main drawback of the PLC splitter: (1) device fabrication process complexity, high technical threshold, the chip by several foreign companies to monopolize the domestic bulk package produced by very few companies. (2) relative to the higher cost of Fused Splitter more at a disadvantage, especially in the low channel splitter.
PLC splitter Packaging Technology
PLC splitter package process includes coupling alignment and bonding operations. Coupling of the PLC splitter chip and the optical fiber array is aligned with both manual and automated, and they depend on the hardware with the six-dimensional precision trimming frame, the light source, power meter, microscopic observation system, while the most commonly used are self-aligned , it is through the optical power feedback closed-loop control is formed, and therefore high coupling efficiency docking accuracy and docking.
PLC splitter has 8 channels and each channel must be accurately aligned to ensure that the relative position between the respective channels due to the manufacturing process of the waveguide chip and an optical fiber array (FA), so only the PLC splitter and the first channel of the FA and 8-channel simultaneous alignment can ensure that other channel aligned, thus reducing the complexity of the package. The most important in the packaging operation at the technical difficulty is the highest coupling alignment operation, it comprises two steps First Harmonic precise alignment. First tune the purpose is to enable the waveguide to light through; the purpose of precise alignment is precise positioning of the completion of the preferred optical power of the coupling point, and it is realized by the program to search the maximum optical power.