We report an investigation of design, fabrication and measurement for photonic crystal fibers developed by YOFC in
three years. The development status of PCFs and their applications are synoptically investigated. In the part of
fabrication process, a technology route of PCF fabrication are reviewed, and the process principle, process control and
realization method are introduced mainly, related to process bottlenecks. Based on different PCFs designed respectively
by Beam-Propagation Method, Plane-Wave Expansion Method or FDTD and the above fabrication process, we probed
into and realized some kinds of PCF samples. The structure parameters, cross-section morphologies, attenuation and
dispersion properties for PCF samples are respectively investigated. We also debate upon the potential application of
In this paper, the DGD (Differential Group Delay) method for beat length measurement of PANDA polarization maintaining (PM) fibers is theoretically analyzed in detailed. And the analysis indicates, regarding the series of silica optical fibers, the error of beat length at different testing wavelength can be ensured less than 2% based on present fiber designs and germanium-doped concentration level. Presently the PMD400 (Polarization Mode Dispersion) analyzer is applied to measure the beat length of polarization maintaining fibers at Yangtze Optical Fiber and Cable Company. Lots of test results shows the DGD method is very reliable, convenient and nondestructive. In practical, the relative deviation of beat length at different wavelength can be kept under 1.5% below based on a number of experimental data. Therefore, the DGD of a PM fiber can be tested at a definite wavelength, such as 1550nm, and then the beat lengths at other operating wavelength can be got according to the relationship between beat length and operating wavelength.
In this paper, we describe a development of a polarization-maintaining fiber by PCVD based process which can be used in the high precision gyroscope and present its measured properties. This kind of fiber is designed as the reduced cladding PMF. The fabrication of the polarization-maintaining fiber is based on the PANDA PMF PCVD based process. Thus, with the reduced cladding, the fiber has better bending properties. Fabrication by the PCVD process, the fiber also has good longitudinal uniformity and a low-loss about 0.374dB/km @ 1310nm, 2.0mm beatlength and -30dB/km crosstalk. It's environmental performance of crosstalk is also good for fiber optic gyroscope. These better properties make this fiber can be used in the high precision gyroscope system.
In this paper, we describe a fabrication process of a long-length and low-loss polarization-maintaining fiber and present the measured optical properties of the polarization-maintaining fiber. The fabrication of the polarization-maintaining fiber is based on the pit-in jacket method, in which the core rod and stress application perform is fabricated by an updated PCVD process. Thus, polarization-maintaining fibers with the long-length not less than 15km can be obtained with a good longitudinal uniformity and a low-loss about 0.423dB/km@1310nm and 0.245dB/km@1550nm. The optical and geometrical properties of the polarization- maintaining fiber were measured. We also tested some special measurements. The results is well matched the specification of the present productions.
In this paper, a 850nm-optimized dispersion-unshifted single-mode optical fiber was introduced. This type of
fiber is completely compatible with G652 series fibers, but its bandwidth at 850nm wavelength has been
optimized in order to fitting the potential applications. This fiber was manufactured by PCVD (Plasma-active
Chemical Vapor Deposition) method. In order to increasing the 850nm bandwidth, the core-RI-profile (Refractive
Index) of this fiber was designed as graded-index profile. With a piece of about 36km length fiber, some relevant
geometric and optical characteristics had been got. The core diameter, MFD (Mode Field Diameter) was about 13
micron and 9.6 micron respectively. The cut-off wavelength and zero-dispersion wavelength was at 1315nm and
1323nm nearly. The attenuation at 1310nm and 1550nm was less than 0.34dB/km and 0.19dB/km respectively.
With all of these results, this 850nm-optimized fiber was completely corresponding with specifications of G652
series of fibers. Meanwhile, OFLB (Over-Filled Launch Bandwidth) test showed the bandwidth at 850nm was
larger than 400MHz.km comparing to about 150MHz.km OFL bandwidth of normal G652 fiber. Because of the
pretty large 850nm bandwidth, this fiber could be possibly used at 850nm wavelength in LAN (Local Area
Network) or DSN (Data-Storage Network) field. In order to validating the compatibility with G652 fibers, the
splice loss between this fiber and normal G652 fiber also had been tested.