Design and demonstration of a novel incoherent optical CDMA system

Abstract

A detailed analysis of the scalability of two-dimensional optical codes is presented and two network deployment architectures for optical code division multiple access (OCDMA) are discussed. We present the architecture and code design for a highly scalable, 2.5 Gb/s per user OCDMA system. The system is scalable to 100 potential and more than 10 simultaneous users, each with BER of less than 10-9. The system architecture uses fast wavelength-hopping, time-spreading codes. Unlike phase sensitive coherent OCDMA systems, this architecture utilizes standard on-off-keyed optical pulses allocated in the time and wavelength domains. This incoherent OCDMA approach is compatible with existing WDM optical networks and utilizes off-the-shelf components. We discuss a novel optical subsystems design for encoders and decoders that enable the realization of a highly scalable incoherent OCDMA system with rapid reconfigurability. We demonstrate the operation of 4 simultaneous users operating at OC-48 (~2.5 Gbit/s) with a power penalty of <;0.5dB and the reduction of multiple-access interference using ultra-fast all-optical sampling with newly proposed TOAD-based OCDMA receiver.