Patent ID: 8204347

Claim:
An optical signal processing device, comprising: a dispersing means for spatially dispersing and outputting an optical signal from a dispersion center in a dispersion plane with an angle depending on a wavelength of the optical signal; a first focusing lens for focusing the optical signal dispersed by the dispersing means; a second focusing lens that is positioned in the vicinity of the dispersing means and between the first focusing lens and the dispersing means; and a signal processing means that is positioned at an opposite side of the dispersing means with respect to the first focusing lens, that is positioned at a position closer than a back focal point of the first focusing lens, and that subjects the optical signal focused by the first focusing lens and the second focusing lens to intensity modulation, phase modulation, or steering, wherein the dispersion center of the dispersing means is positioned in a front focal point position of a two-lens system comprising the first focusing lens and the second focusing lens or the vicinity thereof.