We present the architecture and code design for a highly scalable, 2.5 Gbis per user optical code division multiple access
(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 a fast frequency-hopping, time-spreading codes. Unlike frequency and phase
sensitive coherent OCDMA systems, this architecture utilizes standard on-off keyed optical pulses allocated in the time
and wavelength dimensions. This incoherent OCDMA approach is compatible with existing WDM optical networks and
utilizes off the shelf components. We discuss the novel optical subsystem designs for encoders and decoders that enable
the realization of a highly scalable incoherent OCDMA system with rapid reconfigurability. A detailed analysis of the
scalability of the two dimensional code is presented. Broadcast and select network deployment architectures for
OCDMA are discussed.
Considerable progress has been in the last decade in the fields of photonic networks and ultra-fast optics. The past few years has seen the widespread use of wavelength division multiplexing (WDM) to provide enormous point-to-point capacity in the backbone and metro area networks. Remarkable progress in electronics, in terms of both costs and performance speeds, has to some extent alleviated the 'electronic bottleneck'. Developments in fiber-optics such as novel fiber types and Raman amplification have opened up additional wavelength regions of operation resulting in great expansion of usable fiber bandwidth. There exist unique opportunities for ultrafast technologies - a subject of much interest in the last decade and reaching a point of maturity - to complement these advances and spark the next generation networks.
In our talk, we will mention two networking environments very different from WDM - (1) optical time division multiplexing (OTDM) and (2) optical code division multiple access (OCDMA). We will look at the potential of both these scenarios for different applications, focusing in particular on the latter as an approach that provides maximum flexibility to utilize the immense bandwidth of the optical fiber. We will also describe various ultra-fast technologies that have been developed e.g. .high repetition rate pulsed lasers, ultra-fast optical switches, time delay elements etc. which have a direct relevance to both these types of networks.