Abstract

With the development in the area of femtosecond pulse generation by mode-locked lasers, ^1,2 ultrafast all-optical code-division multiple access (CDMA) networks that can provide more address sequences and simultaneous users than the present CDMA networks^3,4 become increasingly feasible. The corresponding length of a fiber-delay for such a narrow pulse, for example, 100 fs, is in the order of microns. Prime networks³ which generate and select codewords by a parallel combination of fiber-delays, and 2″ networks⁴ which generate codewords by a serial combination of 2×2 couplers and fiber-delays but select codewords in a parallel fashion, are not suitable. The next generation CDMA networks need to be fabricated in waveguides or operated in free space. We first introduce a CDMA network that is particularly suitable for ultrafast all-optical processing in waveguides and then report what we believe to be the first femtosecond CDMA experiment with a programmable encoder in free space.

© 1992 Optical Society of America