Encoder/decoder for optical CDMA

摘要

An encoder according to the present invention is an encoder for encoding an optical wavelength-multiplexed signal compliant with optical CDMA into a code having a code pattern, including: L optical fibers 36 and 42 (where L is an integer equal to or greater than two) each having a plurality of gratings 37 to 47 ; and a circulator 52 for coupling the plurality of optical fibers 36 and 42 . The code pattern contains time bins t 1 to t 3 . A plurality of wavelengths lambda 1, lambda4 and lambda 5 are assigned to the time bin t 1 . If a sum of an optical path difference in each optical fiber from the grating which reflects the optical signal of the wavelength lambda 1 to the grating which reflects the optical signal of the wavelength lambda 4 is calculated for all of the optical fibers 36 and 42 , the sum equals zero.