Patent ID: 7813652

Claim:
An optical pulse time spreading device comprising S optical pulse time spreaders where S is a natural number of 2 or more, that each output an optical pulse that is input to the optical pulse time spreader as a series stream of chip pulses that are sequentially arranged adjacent in time in accordance with an optical phase code, wherein the ith optical pulse time spreader, where i is a set of natural numbers from 1 to S, comprises phase control means that supplies phase differences between said adjacent chip pulses, when adjacent code values are equal, said phase control means supplies a phase difference of 2πM+a i π between adjacent chip pulses corresponding with said code values; and when adjacent code values are different, said phase control means supplies a phase difference of 2πM+(2N+1)π+a i π between adjacent chip pulses corresponding with said different code values, where M and N are integers and the identification parameter a i is a set of distinct real numbers that satisfies 0≦a i ≦2, and a i ≠a j when i≠j, j is a set of natural numbers from 1 to S, and said ith optical pulse time spreader has the corresponding distinct real number for a l .