a caf free 2 2× ultra-long working distance plan apochromatic metrology microscope objective

Abstract

The invention discloses a plan apochromatic measuring microobjective with a 2* overlength working distance and without CaF2. The plan apochromatic measuring microobjective is composed of five lenses including the convex lenses and the concave lenses, the convex lenses and the concave lenses are made of optical glass materials without the CaF2 and are divided into three optical groups, and all the lenses are coaxial with the center of an object plane and sequentially comprise the first convex lens, the second concave lens, the third convex lens, the fourth concave lens, the fifth concave lens and the object plane from left to right. The object plane is imaged at an infinite distance through an optical system. The plan apochromatic measuring microobjective has the advantages that low power measuring microobjective without the CaF2 achieves the plan apochromatic effect; the oversized field of view and the overlength working distance are achieved; the overlength parfocal effect is achieved; the microobjective is made of all-photonic glass, and thus the cost performance is high.

Description

technical field [0001] The invention relates to a microscope objective lens, in particular to a CaF-free 2 2× ultra-long working distance plan apochromatic metrology microscope objective. Background technique [0002] The microscope objective lens is the most important part of the measuring microscope, and its imaging quality directly affects the performance of the measuring microscope. The plan apochromatic microscope objective is the one with the best image quality and the highest grade. In order to correct primary axial chromatic aberration and secondary spectrum at the same time in the objective lens, the traditional method is to introduce optical crystals, such as calcium fluoride CaF 2 etc. as manufacturing materials, but the output of this special optical material is small, brittle, unstable in physical and chemical properties, and large-sized materials are more difficult to obtain. In recent years, some people use special glass (such as TF 3 ) to replace or part...

AI Technical Summary

Problems solved by technology

In order to correct primary axial chromatic aberration and secondary spectrum at the same time in the objective lens, the traditional method is to introduce optical crystals, such as calcium fluoride CaF 2 etc. as manufacturing materials, but the output of this special optical material is small, brittle, unstable in physical and chemical properties, and large-sized materials are more difficult to obtain

Images