9312256 Weiner This project aims at demonstrating the physical feasibility of a novel, high-speed communications network based on encoding and decoding of coherent ultrashort light pulses. In this ultrashort pulse code-division multiple-access (CDMA) environment, a multiplicity of users are connected together via a common fiber optic communications medium; multiple-access is achieved by assigning different, minimally interfering code sequences to different subscriber pairs. A unique attribute of optical CDMA is the use of optical processing, which overcomes electronics bottlenecks and implements directly in the optical domain certain network operations, such as addressing, routing, and security, which traditionally have been performed electronically. Ultrashort pulse CDMA offers a new paradigm for exploiting the terahertz potential bandwidth of optical fibers, which is not fully utilized by other optical networking approaches, and can lead to high-rate local- and metropolitan-area networks with reduced control requirements, for applications such as supercomputer interconnects and multimedia networking. This research aims at experimental tests of an ultrashort pulse CDMA system and of the devices needed to implement such a system. Encoding and decoding of coherent ultrashort pulses were previously demonstrated at visible wavelengths by means of a frequency-domain optical pulse shaping technique; the ability to perform such encoding and decoding is a key motivation for the proposed CDMA network. To date, however, no experiments testing ultrashort pulse CDMA at the infrared wavelengths compatible with fiber optic technology have yet been conducted. The current proposal aims at assembling a simple ultrashort pulse CDMA testbed, including fiber transmission at 1.5um, in order to critically test the physical layer performance of this technique. Research will also be performed on several ultrashort pulse component technologies, such as ultrafast fiber lasers, integrated encoding and decodin g devices, fiber dispersions compensation techniques, and nonlinear optical devices, which will lead to more compact and practical implementations of ultrashort pulse CDMA networks. ***
