Abstract
Low-loss optical fibers are essential for laser applications and fiber-optic communications. This paper
reviews the history and technology for reducing the transmission loss of optical fibers. For today’s
optical fibers, the key technology for reducing loss is to reduce the Rayleigh scattering loss. Pure-silicacore
fiber (PSCF) with low Rayleigh scattering has been developed, with a record-low loss of 0.1484
dB/km at 1570 nm. Commercial PSCF has low loss less than 0.17dB/km at 1550 nm, whereas the loss
of standard single mode fiber with a Ge-doped core is about 0.19dB/km. We also introduce lownonlinearity
fibers with an effective area larger than 130 μm2. Low-loss and low-nonlinearity fibers,
which can effectively improve the optical signal-to-noise ratio, should be best suited for large capacity
and long-haul transmissions in near future. Evolutional fibers such as hollow-core fiber are anticipated
to ultimately realize low loss and low nonlinearity.
