Patent ID: 7280759

Claim:
An optical transmission system for transmitting a signal lightwave comprising a plurality of component signals each having a different wavelength, the optical transmission system comprising: (a) at least one optical transmitter; (b) at least one optical receiver; (c) an optical fiber transmission line that: (c1) is installed between the at least one optical transmitter and the at least one optical receiver; and (c2) has a length of at most 150 km; and (d) an optical component that: (d1) is installed between the at least one optical transmitter and the at least one optical receiver; and (d2) gives a loss to the signal lightwave; the component signals including a component signal having a wavelength of λ a and a component signal having a wavelength of λ b ; the optical transmission system being designed such that: (e) the total transmission loss in the optical fiber transmission line is smaller at a wavelength of λ b than at a wavelength of λ a ; (f) the insertion loss of the optical component is larger at a wavelength of λ b than at a wavelength of λ a ; and (g) the difference in power between the component signal having a wavelength of λ a arriving at the at least one optical receiver and the component signal having a wavelength of λ b arriving at the at least one optical receiver is smaller than the difference in the total transmission loss in the optical fiber transmission line between the wavelengths λ a and λ b .