Optical fiber grating coder for use in optical code division multiple access, fabricating method and apparatus therefor

A method for fabricating an optical fiber grating coder, comprising:

• a) providing a light source;
• b) providing an amplitude mask designed for predetermined codewords;
• c) providing a chirped phase mask;
• d) providing an optical fiber;
• e) exposing the optical fiber to a coherent light beam irradiated from the light source, which passes sequentially through an optical device, the amplitude mask, and the chirped phase mask to reach a core of the optical fiber;
• and
• f) forming a plurality of chirped gratings implementing the predetermined codewords in the core of the optical fiber in the form of striations,
• wherein the plurality of chirped gratings function as an optical fiber grating coder, and
• wherein the amplitude mask and the chirped phase mask are provided between the optical device and the optical fiber, and the chirped phase mask is located between the amplitude mask and the optical fiber.

An apparatus for fabricating an optical fiber grating coder, comprising:

• a light source;
• an optical device;
• an amplitude mask designed for predetermined codewords;
• a chirped phase mask;
• and
• an optical fiber,
• wherein a coherent light beam irradiated from the light source reaches a core of the optical fiber, which passes sequentially through the optical device, the amplitude mask, and the chirped phase mask to imprint a plurality of chirped gratings implementing the predetermined codewords in the form of striations into the core of the optical fiber, and
• wherein the amplitude mask comprises a plurality of sections and selectively transmits the coherent light beam on the basis of a wavelength of the coherent light beam.