Optical splitter is suitable for a fiber optic signal to be decomposed into multi-channel optical signal output.
Role of optical splitter
(1) It divides out a main light source into 1-N optical path.
(2) It synthesizes 1-N optical path into a main light source and recovers this source.
Working principle
In the single-mode optical fiber of the optical signal when the energy of the light is not completely concentrated in the core communication, a small amount is spread through the cladding near the core, that is, in the two fibers the core sufficiently close, then the mode field of the light transmitted in an optical fiber can enter another one optical fiber, optical signals in the two optical fibers to obtain a re-allocation
Technology
There are two types of optical splitters to meet the need for spectroscopy. One is fused biconical taper splitter (FBT Splitter) made by the traditional optical passive device manufacturers using the traditional biconical taper coupler technology. The other one is planar optical waveguide splitter (PLC Splitter) based on optical integration technology. Both devices have their own advantages. Depending on the occasion and demand, users can rationally choose different types of spectroscopic devices following a brief introduction of the two devices, which is just for reference.
FBT Splitter
Fused biconical taper (FBT) technology is tied to two or more fibers, and then melted in a cone machine, pull tensile and real-time monitoring of changes in splitting ratio, melt tensile splitting ratio to meet the requirements end, wherein one end of a fiber optic reserved ( The remaining cut off) as the input terminal and the other end a multitude of road outputs. Mature tapering process can only pull 1 × 4. 1 × 4 or more devices, with a plurality of 1 × 2 connected together. Then the whole package in the splitter box.
Main advantages
(1) The taper coupler has more than 20 years of history and experience, many equipment and process just follow it, development funds only a few one-tenth or even a few hundredth of PLC
(2) Raw materials have easy access to the quartz substrate, optical fiber, heat shrink tubing, stainless steel pipe and less plastic, a total of not more than one U.S. dollars. investment in machinery and equipment depreciation costs less, 1 × 2,1 × 4 the low channel splitter low cost.
(3) Splitting ratio can be real-time monitoring, you can create unequal splitter.
Main drawback
(1) Loss of the optical wavelength-sensitive, generally according to the wavelength selection device, which in the triple play during use is a fatal defect, since the optical signal transmitted in the triple play there 1310nm, 1490nm, 1550nm multi kinds of wavelength signals.
(2) Poor uniformity, 1×4 nominal about 1.5dB away, 1 × 8 or more away from larger, can not ensure uniform spectroscopic, which may affect the overall transmission distance. A demultiplexer
(3) Insertion loss varies with temperature variation is greater (TDL)
(4) The volume is relatively large, so the reliability will be reduced, and the installation space is restricted.
PLC Splitter
The planar waveguide technology using a semiconductor production process, the optical waveguide branching device branching function is completed on the chip, and can be implemented on one chip up to 1X32 splitter, then, at both ends of the chip package input terminal and an output coupled respectively end multi-channel fiber optic array.
Main advantages
(1) Loss is insensitive to the wavelength of transmitted light, to meet the different wavelengths of the transmission needs.
(2) Splitting the uniform, the signal can be uniformly assigned to a user.
(3) Compact structure, small size (Borch 1 × 32 size: 4 × 7 × 50 mm), can be directly installed in the various existing junction box, no special design leave a lot of space for installation.
(4) Only a single device bypass passage can achieve much more than 32 channels.
(5) The multi-channel, low cost, stars ones more and more obvious cost advantages.
Main drawback
(1) Device fabrication process complexity, high technical threshold, the chip is several foreign companies to monopolize domestic bulk package production enterprise only Borch rarely several.
(2) Relative to the higher cost of Fused Splitter more at a disadvantage, especially in the low channel splitter.
Contrasting the main parameters of the two devices
(1) Both devices have their own advantages in terms of price and performance. The two technologies are constantly upgraded, continue to overcome their disadvantages. Pull cone splitter being addressed disposable tapering in small quantities and poor uniformity; the waveguide splitter also reduce the cost to make unremitting efforts, the two devices 1X8 cost almost the same, with channels increase in the price of a planar waveguide splitter better.
(2) How to choose the two devices? The key is the occasion and the needs of users in terms of. In volume and the wavelength of light is not very sensitive applications, especially in the case of shunt less, the choice of tapering optical splitter relatively affordable, such as independent data transmission is optional 1310nm pull cone splitter, TV video network Select the the 1550nm pull cone splitter; triple-play FTTH require multiple wavelength optical transmission and more occasions should be used in the optical waveguide splitter. At present, the majority of domestic companies FTTH trial network multi-pull cone splitter, which is due to the many designers are not familiar with the PLC device, the few domestic companies producing such devices. Japan and the United States FTTH really commercial operation of the market is almost entirely planar optical waveguide splitter.
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