Patent ID: 7050676

Claim:
An apparatus for performing, by optical code division multiplex access (OCDMA), at least one of encoding and decoding of wavelength-division-multiplexed (WDM) light, comprising: an optical input/output section for handling input/output of the wavelength-division-multiplexed light; and N fiber gratings (where N is an integer equal to or greater than two) which are in a series connection to the optical input/output section, wherein, each of the N fiber gratings has a sampled grating structure defining a plurality of reflection wavelength bands; and an interval ΔT between central values of the reflection wavelength bands of the sampled grating structure is equal to an interval S between central wavelengths of wavelength bands contained in the wavelength-division-multiplexed light, and the central values of the respective reflection wavelength bands differ from one fiber grating to another at least during operation.