Patent ID: 8797638

Claim:
A wavelength selective optical switch device comprising: an incidence and exit part where a signal beam made of light of a multiplicity of wavelengths enters and a signal beam of a selected wavelength exits; a wavelength dispersion element that spatially disperses a signal beam according to the wavelength thereof and multiplexes reflected light; a condensing element that condenses the light dispersed by the wavelength dispersion element onto a two-dimensional plane; a wavelength selection element that uses a multilevel optical phased array arranged in a position to receive incident light developed on an xy-plane made of an x-axis direction and a y-axis direction perpendicular thereto developed according to a wavelength, having a multiplicity of pixels arrayed in a lattice on the xy-plane, and that cyclically changes the phase shift amount in the y-axis direction to a sawtooth wave pattern for each pixel on the x-axis; and a wavelength selection element drive part that drives an electrode for each pixel arrayed in an xy direction of the wavelength selection element, generates a composite wave of two or more sawtooth waves along the y-axis for all pixels on the y-axis that have an x-coordinate common with at least one pixel on the x-axis, changes a phase shift amount according to the composite wave, and reflects light of a wavelength applied to that pixel in a plurality of directions.