| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent an influence of fluctuation of wavelength of an optical pulse with single wavelength even when the wavelength fluctuates and to reduce crosstalk between optical signals of channels to which the adjacent wavelengths are assigned, respectively. <P>SOLUTION: This optical pulse time spreading device is constituted by being provided with first to U-th optical pulse time spreading units in which SSFBs to be constituted by arranging N unit FBGs in series along the length direction of an optical fiber are utilized. To each of the unit FBGs constituting the optical pulse time spreading units, refractive index modulation is given as a function obtained by multiplying the refractive index modulation as a diffraction grating by a sinc function, and phase difference between Bragg reflection light from a refractive index modulation area to be enveloped by a peak curve which takes the largest maximal values of the sinc function, which gives an envelope for connecting the maximal values of the function and Bragg reflection light from a refractive index modulation area to be enveloped by a peak curve which takes the largest maximal values of the sinc function in the adjacent unit FGB is set to odd times of half-wavelength of the Bragg reflection light. <P>COPYRIGHT: (C)2011,JPO&INPIT |
