WAVELENGTH SELECTIVE SWITCH AND OPTICAL CROSS-CONNECT DEVICE INCLUDING WAVELENGTH SELECTIVE SWITCH

Provided are a wavelength selective switch capable of dealing with a broadband wavelength range with reduced crosstalk and an optical cross-connect device including the wavelength selective switch. The wavelength selective switch includes an optical input port; an optical output port; a wavelength dispersion unit that spatially separates light incident from the optical input port for each of wavelengths and emits the separated light such that an emission angle of the incident light varies for each of predetermined wavelength ranges; and a deflection unit that couples light incident from the wavelength dispersion unit to the optical output port by deflecting the incident light such that a reflection angle or a transmission angle of the incident light is variable for each of wavelengths, in which the wavelength dispersion unit includes a wavelength dispersive element and a position control mechanism that reversibly changes a position or an angle of the wavelength dispersive element or both the position and the angle with respect to the optical input port.