OPTICAL PULSE TIME SPREADER AND OPTICAL CODE DIVISION MULTIPLEX TRANSMITTER

摘要

Both the ratio P/W of the peak value P and the sub-peak value W of an auto-correlation waveform and the ratio P/C of the peak value P of the auto-correlation waveform and the maximum peak value C of a cross-correlation waveform are large. A phase control means has a structure in which an SSFBG (40) where fifteen unit FBGs are arranged in series along the waveguide direction is fabricated in the core of an optical fiber (36) comprising the core (34) and a clad (32). The difference ?n between the maximum and minimum effective refractive indexes of the optical fiber is 6.2×10^-5. The phase difference between the Bragg reflection lights from two unit diffraction gratings adjacent in the longitudinal direction and providing equal encoded values is given by 2pM+(p/2) where M is an integer. The phase difference between the Bragg reflection light from two unit diffraction gratings adjacent in the longitudinal direction and providing different encoded values is given by 2pM+(2N+1)p+(p/2) where M and N are integers.