Diffractive optical element and method for manufacturing same

Abstract

A diffractive optical element includes at least a first diffractive element and a second diffractive element. The conditional expression 0.5≦D/DS≦0.9 is preferably satisfied where DS denotes the summation of the optimum designed groove height of the first diffractive element d 1 S and that of the second diffractive element d 2 S, and D denotes the summation of an actual groove height of the first diffractive element d 1 and that of the second diffractive element d 2 . At least one of the first diffractive element and the second diffractive element is made of glass. At least one of the first diffractive element and the second diffractive element is made of resin. The optimum designed value of groove heights of the diffractive optical element are determined so as to satisfy a condition for correcting chromatic aberration at both d-line and g-line.

1 . A diffractive optical element comprising:
 at least a first diffractive element and a second diffractive element, wherein   the following conditional expression is satisfied:
   0.5 ≦D/DS≦ 0.9 
   where DS denotes a summation of optimum designed groove heights of the diffractive optical elements, and D denotes a summation of actual groove heights of the diffractive optical elements.   
   
   
       2 - 39 . (canceled)