Patent ID: 8761554
Filing Date: 2014-06-24
Classification: G02B

Abstract:
1. A wavelength selective switch, comprising: an input/output portion including at least twenty input/output ports; a dispersive portion for dispersing wavelength-multiplexed signal light incident from the input/output port; a condensing optical system for condensing a plurality of signal light beams dispersed by the dispersive portion; and a deflection portion having a plurality of deflection elements for deflecting, along a second direction perpendicular to the dispersion direction of the dispersive portion, the plurality of signal light beams condensed by the condensing optical system, so as to allow the signal light beams to be incident on any of the input/output ports, the condensing optical system having the aberration amount of the meridional component in a sagittal coma aberration maintained substantially constant irrespective of an angle formed between the optical axis of the condensing optical system and the signal light beam incident on the condensing optical system from the input/output portion, at an incident position of the incident signal light beam at a certain height in the second direction.