Patent ID: 9001420
Filing Date: 2015-04-07
Classification: G02B

Abstract:
1. A microscope optical system comprising: an objective lens which has a diffractive optical element and converts light from an object into a substantially parallel light flux; and a second objective lens which forms an image of the object by focusing the substantially parallel light flux from the objective lens, wherein in case where an m-th order diffracted light from the diffractive optical element is used for the image formation, the following expression is satisfied: when the light of a maximum NA emitted from the object located on an optical axis enters the diffractive optical element, where θ is the incident angle on the second objective lens of the diffracted light having an order of diffraction different from the order of the m-th order diffracted light from the diffractive optical element, and D [mm] is a diameter of an entrance pupil to the second objective lens.