DIFFRACTIVE ELEMENT AND METHOD FOR MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a pseudo-blazed diffraction element having a grating pattern with fine grating pitches with high accuracy. SOLUTION: A first diffractive element and a second diffractive element 3 having mirror symmetric grating patterns are produced. The first and second diffractive elements are laminated as opposing to each other. The elements are shifted from the aligned state of the grating patterns by about 1/4 of the grating pitch Δ in the diffraction direction X of light and fixed with an adhesive 4. The shift distance is adjusted during the production or controlled during used by using a piezoelectric element.