US 6,549,334 B1Granted

Transmission illumination type differential interference microscope

AssigneeNikon Corporation

InventorsTatsuro Otaki, Kumiko Otaki

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Abstract

In the transmission illumination type differential interference microscope, light in a given polarized state is separated by a first birefringent optical member 1 into two linearly polarized light components L1 and L2 and both of the polarized light components are converted into parallel light by means of a condenser lens 13. The object being examined 15 is illuminated by the polarized light components which are then converted into convergent light by an objective 16. Both of the polarized light components are then synthesized into a single light beam by a second birefringent optical element 2 and both of the polarized light components of the synthesized light beam are caused to undergo polarization interference by an analyzer 17 so that an enlarged image 18 of the object being examined 15, is formed. At least one of the first and second birefringent optical members 1 and 2 is formed by joining one isotropic prism 1g or 2g, consisting of an isotropic optical material, and one birefringent prism 1a or 2a, consisting of a birefringent optical material.

Claims18

Dependent claims

A differential interference microscope comprising:

a light source capable of providing a polarized light;
a first birefringent optical member capable of separating the light from the light source into two linearly polarized light components having planes of vibration perpendicular to each other;
a condenser lens capable of conducting the two linearly polarized light components, separated by the first birefringent optical member, to an object being examined;
an objective capable of focusing each of the two linearly polarized light components from the object being examined;
a second birefringent optical member capable of synthesizing each of the two linearly polarized light components from the object being examined;
and
polarization interference means for synthesizing the linearly polarized light components,
wherein the first birefringent optical member includes:
a first wedge-shaped prism made of an isotropic optical material, and
a second wedge-shaped prism positioned between the condenser lens and the first wedge-shaped prism and made of a birefringent optical material having a center thickness of between about 0.4 and 0.6 mm, and
wherein the second birefringent optical member includes a third wedge-shaped prism made of a birefringent optical material having a center thickness of between about 0.4 and 0.6 mm, and a fourth wedge-shaped prism positioned between the third wedge-shaped prism and the polarization interference means and made of an isotropic optical material.

8 more elements

Dependencies are inferred from the claim text.