Transmission loss of a 125- mu m diameter PANDA fiber with circular stress-applying parts

The transmission loss of a 125- mu m diameter polarization-maintaining and absorption-reducing optical fiber (the PANDA fiber) with circular stress-applying parts (SAPs) has been investigated. The loss is calculated at a 1.55- mu m wavelength for SAPs consisting of B/sub 2/O/sub 3/ doped silica glasses. The experimental measurements show the validity of the analysis. It is shown that, when the half distance between SAPs is more than 2.2 times the core radius, the additional transmission loss due to B/sub 2/O/sub 3/ absorption is less than 0.05 dB/km with normalized frequency of 2.2 to 2.4 and a B/sub 2/O/sub 3/ dopant concentration of 20 mol.%. As a result, it has been confirmed that transmission losses of 125- mu m diameter PANDA fibers can be comparable to those of commercially available single-mode optical fibers. >