| 摘要 |
PROBLEM TO BE SOLVED: To easily determine a driving range suitable for a diffraction optical element without actually measuring characteristics of an amount of diffraction light with respect to an input parameter, and to efficiently control the diffraction optical element.SOLUTION: A control device of a diffraction optical element comprises: a light-amount measurement unit that actually measures an amount of light of diffraction light to be reflected by the diffraction optical element as an amount of reflection light when making light incident upon the diffraction optical element; a light-amount calculation unit that calculates the amount of reflection light on the basis of a characteristic of the amount of diffraction light indicative of a change in the amount of reflection light relative to a change in parameters; and a range determination unit that determines a driving range on the basis of a difference between the amount of reflection light actually measured by the light-amount measurement unit under the same condition and the amount of reflection light calculated by the light-amount calculation unit thereunder, and the characteristic of the amount of diffraction light.SELECTED DRAWING: Figure 1 |
