We demonstrate an error-free four-user 10-Gb/s/user optical code-division multiple-access network testbed employing the spectral phase encoded time spreading technique and nonlinear thresholding. The experiments successfully overcome multiuser interference, resulting in error-free operation.

This paper demonstrates a high-performance optical-code-division-multiple-access (O-CDMA) network testbed using the spectral phase encoded time spreading (SPECTS) method. Through additional time and polarization multiplexing, a total of 32 10-Gb/s users are supported while sharing eight O-CDMA spreading codes. User detection is achieved with time gating and nonlinear thresholding to suppress the multiaccess interference of other users. Incorporation of forward error correction successfully reduces the performance loss imposed by coherent beat interference, resulting in error-free performance (BER<10-11), significant per-user power penalty reduction, and the elimination of a bit-error-rate noise floor. The testbed also applies bandwidth suppression within the encoders and decoders, yielding a 52% increase in spectral efficiency (25 References).

This letter presents a high-capacity optical code-division multiple-access (O-CDMA) network testbed based on the spectral phase-encoded time-spreading technique. Two 10-Gb/s/user O-CDMA network architectures (time-slotted and time-slotted polarization multiplexed) are investigated. The first O-CDMA network testbed architecture utilizes eight encoders and a decoder to produce 16 users equally distributed in two time slots while the second architecture evenly distributes 32 users in two time slots and two polarizations. The 16-user testbed achieved error-free performance. The 32-user testbed obtained bit-error rates below 10(-8) without using forward-error-correction techniques.

Error-free operation of a 12 x 10 Gbit/s synchronous, time-slotted spectral phase-encoded time-spreading optical code division multiple access (O-CDMA) network testbed without using forward-error-correction (FEC) is demonstrated. A nonlinear optical loop mirror time gate and nonlinear thresholding minimise multiuser interference.