US 2009/0269064 A1 · Optical CDMA by Self Heterodyne Filtering

Abstract

A new method and system for Optical Code Division Multiple Access (OCDMA) transmission, in which channel selection and rejection are based on dynamic self-heterodyne filtering using differential time delays applied to the data-modulated signals to code and decode the transmissions in each channel. Mach-Zender Interferometers having characteristic delays between their arms are a simple way of performing this coding and decoding. The technique enables the use of narrow linewidth sources and low spectrum spreading. Consequently this technique can be used in next-generation all-optical dynamic networks allowing bandwidth sharing on the one hand, while at the same time eliminating the need for network management and optical switching. Preliminary theoretical calculations predict the system support of up to 15 channels at a data rate of 1 GHz.

Claims29

Dependent claims

A method of transmitting information optically through a medium comprising the steps of:

generating at least two mutually time delayed optical signals frequency-modulated with said information, said signals having a first differential time delay between them;
transmitting said mutually time delayed signals over said medium, and receiving said transmitted signals;
splitting said received signals into at least two parts, and applying a second differential time delay to said at least two parts of said received signals;
adding said differentially time delayed parts of the received signals to generate an output optical signal, and
detecting said output optical signal on an optical receiver having a limited bandwidth such that output optical signals having a frequency outside of said receiver bandwidth are rejected.

2 more elements

Dependencies are inferred from the claim text.

Optical CDMA by Self Heterodyne Filtering

Life of this patent

Optical CDMA by Self Heterodyne Filtering

Life of this patent

Abstract

Claims29