MICROSCOPE OBJECTIVE LENS

摘要

PROBLEM TO BE SOLVED: To provide a microscope objective lens which has a numerical aperture of the extent of 0.65 and has a color aberration corrected in a wide wavelength region ranging from ultraviolet to near-infrared (405 nm to 1,064 nm). SOLUTION: The microscope objective lens is composed of a positive first lens group G1, a positive second lens group G2 and a negative third lens group G3 in the order from the object side, wherein an achromatic lens, in which a positive lens and a negative lens are joined, is disposed on each of G1 to G3 at least by one, a diffraction optical face is formed on at least one face of an optical element constituting G2 and, when a partial dispersion ratio of glass material and absolute value of a difference of the Abbe number of positive lens and negative lens of an achromatic lens of G1 areΔP1,Δvd1, a partial dispersion ratio of glass material and absolute value of a difference of the Abbe number of positive lens and negative lens of an achromatic lens of G2 areΔP2,Δvd2, a focal distance of the whole system is f and a focal distance of G1 is f1, the microscope objective lens satisfies the following relations:ΔP1>0.04,ΔP2>0.04,Δvd1>20.0,Δvd2>25.0 and 1.0