| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pulse time spreading device which can ensure a large energy distribution ratio of a cross-correlation wave component to an autocorrelation wave component and ensure peak intensity of an autocorrelation wave which is amply larger than the peak intensity of a cross-correlation wave. <P>SOLUTION: In first to S-th optical pulse time spreaders (S is an integer satisfying S≤N), N unit FBGs from an input/output end are arranged side by side, in this order starting from the first to the N-the unit FBG. A relative phase shown in the upper stage of each of the upper parts of the respective unit FBGs is set in the respective unit FBGs. An optical pulse 29-n to be input to a first optical pulse time spreader is input to an optical pulse time spreader 36-n via an optical circulator 30-n, subjected to time spreading by the first to the N-th unit FBGs, generated as a chip pulse train 35-n and output via the optical circulator. A relative phase respectively equal to 0 is given to a first chip pulse constituting the chip pulse train, a relative phase equal to d<SB>1</SB>(=2π(a+(n-1)/N)), ..., is given to the second chip pulse, and a relative pulse equal to (N-1)d<SB>1</SB>is given to the N-th chip pulse, respectively. Parameter a is an arbitrary real number that satisfies the relation 0≤a<1. <P>COPYRIGHT: (C)2009,JPO&INPIT |
