Patent ID: 8335421

Claim:
An optical transmission system comprising: an optical transmitting unit that outputs at least one optical signal having a wavelength included in an operation wavelength band; and a holey fiber that is connected to the optical transmitting unit, the holey fiber including a core through which the optical signal is transmitted, a cladding formed around the core, the cladding including a plurality of holes formed around the core in a triangular lattice shape, wherein the holey fiber transmits the optical signal in a single mode, and a bending loss of the holey fiber is equal to or less than 5 dB/m at a wavelength in the operation wavelength band when the holey fiber is wound at a diameter of 20 millimeters, the core of the holey fiber is surrounded by not less than four layers of the holes, a confinement loss of the holey fiber is equal to or less than 0.001 dB/km at the wavelength in the operation wavelength band, and design parameters of the holey fiber satisfy 0.4≦ d/Λ≦ 0.43, Λ≦−0.518λ s 2 +6.3617λ s +1.7468, and λ≧−0.0801λ l 2 +3.6195λ l +0.3288 where Λ is lattice constant of the triangular lattice in micrometers, d is diameter of each of the holes in micrometers, λ l is a maximum wavelength in the operation wavelength band in micrometers, and λ s is minimum wavelength in the operation wavelength band in micrometers.