CONTROL APPARATUS AND CONTROL METHOD FOR SPATIAL LIGHT MODULATOR

摘要

A control apparatus includes a lens, an SLM presenting a modulation pattern on a modulation plane and outputting modulated light L2 for forming light spots P1 and P2 on a pupil plane of the lens, an imaging device imaging a fringe pattern image formed on a focal plane of the lens and generating image data Da indicating the fringe pattern image, a calculation unit calculating at least one kind of parameter among an intensity amplitude, a phase shift amount, and an intensity average from the image data Da, an analysis unit obtaining a deviation in relative positions of an optical axis of the lens and a reference coordinate of the modulation plane based on the parameter, and a changing unit changing an origin position of the reference coordinate so that the deviation in the relative positions is decreased.

主权项

1. A control apparatus for a spatial light modulator, comprising:
a lens; a spatial light modulator including a modulation plane, in which a plurality of modulation pixels are arrayed two-dimensionally, and configured to modulate light based on a first modulation pattern and output first modulated light for forming a first light spot and a second light spot on a pupil plane of the lens; an image sensor including an imaging plane, in which a plurality of photoelectric conversion pixels are arrayed two-dimensionally, and configured to capture an image of a first fringe pattern image formed on a focal plane of the lens by the first modulated light on the imaging plane and generate first image data indicating a light intensity distribution of the first fringe pattern image; and a processor electrically coupled to the image sensor and the spatial light modulator, and the processor configured to: calculate at least one kind of first parameter among an intensity amplitude, a phase shift amount, and an intensity average based on the first image data, obtain a deviation in relative positions of an optical axis of the lens and a reference coordinate of the modulation plane based on the first parameter, and control an origin position of the reference coordinate on the modulation plane so that the deviation in the relative positions is decreased.