Patent ID: 6850665

Claim:
An optical device comprising: an input fiber having a cladding and a core for receiving a light input; a target fiber having a cladding and a core; the cladding of the input fiber and the cladding of the target fiber being close together to define a coupling region in which light is coupled from the cladding of the input fiber to the cladding of the target fiber; a first perturbation for wavelength-selective coupling of light from the core of the input fiber into the cladding of the input fiber; and a second perturbation for wavelength selective coupling of light from the cladding of the target fiber into the core of the target fiber, wherein at least one of the first and second perturbations is in the cladding and the first perturbation and the second perturbation do not overlap, and the coupling region is located between the first and second perturbations in a lengthwise direction.