At present, low loss and pure quartz optic fibers with max. 0.17 dB/km attenuation at 1550 nm wavelength and max. 0.31 dB/km at 1310 nm wavelength are ready for use. Low loss and pure quartz optic fibers have at least 0.02 dB/km lower spectral attenuation in comparison to the standard ones G.652D. In such fibers, the retention of flat spectral characteristics within the transmission windows provide the possibility of achieving sub- stantially smaller deviations of attenuation:
– 1310 nm (+ 20 nm / -35 nm) wavelength – max. deviation is 0.03 dB/km
– 1550 nm ( + 25 nm / -25 nm) wavelength – max. deviation is 0.02 dB/km with the retention of 1625 nm attenuation 0.20 dB/km.