Study On Pdl Of The Small Splitting Ratio Of Fused Dwc

The development of FTTH broadband network will directly affect the development of optical networks and optical device technologies. The small splitting ratio (less than20%) of optical splitters are widely used in optical passive network, fiber amplifiers and optical testing equipments. The splitter Tap (Test Access Point) of an optical monitoring system is to provide a complete, accurate data monitoring access point. But the polarization dependent loss (PDL) of optical splitter can’t be ignored in application. On the market, the PDL is less than0.2dB when the output power of optical splitter is less than5%. So the industrial difficulty has been how to produce low PDL single-window, dual-window broadband optical splitter.This paper theoretically analyze and simulate the PDL of the optical splitter in detailed, and has given the optimized conditions of making low PDL optical splitter in the experiment, then the maximum PDL is less than0.1dB at that speed. The major work of this paper is as follows:(1) Based on weakly fused coupled mode, the polarization dependent loss (PDL) of the optical-fiber splitters with the different splitting ratio, the dual-window and wide-band, firstly are calculated and it is found that the optical splitter with the wavelength of1550nm and the coupling ratio of5/95have the maximum PDL in this paper, then it gives the simulation curve about the coupling power and PDL with pulling length of the splitting ratio of5/95,2/98optical splitter by using Mathcad.(2) Then, the impact of the different pulling speed on PDL of the optical splitter with the splitting ration of5/95、2/98, is experimentally investigated and it is found that the maximum PDL of the splitting ration of5/95optical splitter is less than0.1dB when the drawing speed is in the range of0.18mm/s～0.27mm/s, and the maximum PDL of the splitting ration of2/98optical splitter is less than0.1dB when the drawing speed is in the range of0.15mm/s0.23mm/s, and have found the optimized conditions of the other splitting optical splitter to make the maximum PDL of optical splitter is less than0.1dB.(3) Finally, the reasons affecting the trends of PDL variation is analyzed, which including form birefringence caused by the geometry of the fiber shape, the non-roundness of the geometric core and the non-circular symmetry of core refractive index, the distortions caused by the temperature field in the process of making optical splitter, stress birefringence caused by pulling speed and the way of two optical fiber playing twisted360°tapered in the pulling process, it is finally shown that the fused degree is the dominant factor of the impact on the PDL variation.