Patent ID: 7167651

Claim:
A code division multiplexed optical communication system comprising: at least one transmitter configured to receive a first data stream and transmit a code division multiplexed optical signal comprising a number K code words modulated with first data from said first data stream(where K is an integer greater than 1); wherein the transmitter comprises: a pulsed light source: a transmitter splitter having a splitter input and a plurality of splitter outputs, the transmitter splitter having the pulsed light source input thereto and outputting at least a number K identical code beams; K code modulators, each code modulator configured to receive one of the at least K identical code beams and output a corresponding data-modulated code word; wherein each of the code modulators comprises: a pulse spreader configured to receive one of the K identical code beams, said one of the K identical code beams comprising a single pulse within a predetermined time window, the pulse spreader being further configured to output an imprinted code beam having a number P modulated pulses within that time window; and a data modulator configured to receive said imprinted code beam from the pulse spreader and modulate said imprinted code beam with data from said first data stream to thereby form a data-modulated code word; wherein the pulse spreader comprises: a 1:P splitter configured to split one of said K code beams input thereto into P identical code beams (where P is an integer greater than 1), each code beam having a single pulse; P chip modulators, each chip modulator configured to receive a single pulse and output a delayed modulated pulse, the p-th chip modulator comprising: a delay circuit configured to delay said single pulse by (p-1)*C, where C=T/P is a chip period, T being a symbol period (T is an integer greater than 1) and p representing an index; and a chip modulation circuit configured to code-modulate the delayed single pulse by a p-th code value belonging to an orthogonal code of length P; and a P:1 combiner configured to combine code-modulated outputs from the P chip modulation circuits into the imprinted code beam which comprises P pulses within said symbol period T; and a transmitter combiner configured to combine the K data-modulated code words into a code division multiplexed optical signal; wherein the K data-modulated code words are orthogonal to one another; and at least one receiver optically connected to the first transmitter and configured to receive said code division multiplexed optical signal, detect and demodulate said K code words within the code division multiplexed optical signal, and output said first data, wherein the K code words are orthogonal to one another.