Imaging incident angle tracker

Patent metadata

Field	Value
Publication number	US-10955683-B2
Application number	US-201816186064-A
Country	US
Kind code	B2
Filing date	Nov 9, 2018
Priority date	Nov 10, 2017
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

An imaging incident angle tracking device, including: a light source; a first and second beam splitters or dichroic mirrors; a position sensitive detector; wherein the first and second beam splitters or dichroic mirrors are configured to direct light from the light source to a window surface through an objective lens; the first and second beam splitters or dichroic mirrors is further configured to direct the light reflected from the window surface and through the objective lens into the position sensitive detector. A positioning system, including: a baseplate; a platform; a plurality of strut assemblies connecting the baseplate and the platform; wherein each of the strut assembly includes: a linear actuator; a first flexure assembly and a second flexure assembly at the first and second ends of the strut assembly; the first and second flexure assemblies are rigid along and flexibly bendable orthogonal to the length of the strut assembly.

First claim

What is claimed is:

1. An imaging incident angle tracking device, comprising:
a light source;
a first beam splitter or dichroic mirror;
a second beam splitter or dichroic mirror; and
a position sensitive detector;
wherein the first and second beam splitters or dichroic mirrors are configured to direct light from the light source to a window surface through an objective lens; the first and second beam splitters or dichroic mirrors are further configured to direct the light reflected from the window surface and through the objective lens into the position sensitive detector such that an angle of the window surface relative to the objective lens is determined from the detected position of the incident light on the position sensitive detector.

2. The imaging incident angle tracking device of claim 1 , wherein the position sensitive detector is a quadrant position sensitive detector.

3. The imaging incident angle tracking device of claim 1 , further comprising a processor configured to use a signal detected by the position sensitive detector to control a stage on which the objective or window surface is mounted.

4. The imaging incident angle tracking device of claim 1 , further comprising a lens arranged between the first and second beam splitters or dichroic mirrors to focus the light onto the objective lens, wherein the light source is a point light source and placed at a conjugated Fourier plane of the objective lens.

5. The imaging incident angle tracking device of claim 4 , further comprising a first aperture placed in front of the light source and a second aperture placed in front of the position sensitive detector, such that the point light source in conjunction with the first aperture is off-centered from the optics axis such that the light comes out below the objective lens at an angle, and that only reflections from a desired depth below the objective lens pass through the second aperture into the position sensitive detector.

6. An imaging system comprising an imaging microscope equipped with an imaging incident angle tracking device that comprises:
a light source;
a first beam splitter or dichroic mirror;
a second beam splitter or dichroic mirror; and
a position sensitive detector;
wherein the first and second beam splitters or dichroic mirrors are configured to direct light from the light source to a window surface through an objective lens; the first and second beam splitters or dichroic mirrors are further configured to direct the light reflected from the window surface and through the objective lens into the position sensitive detector such that an angle of the window surface relative to the objective lens is determined from the detected position of the incident light on the position sensitive detector, and
the imaging microscope is mounted on a positioning system that has six degrees of freedom.

7. The imaging system of claim 6 , wherein the positioning system is a hexapod.

8. A positioning system, comprising:
a baseplate;
a platform; and
a plurality of strut assemblies;
wherein a first end of each of the plurality of strut assemblies is connected at a predefined location on the top surface of the baseplate and a second end of each of the plurality of strut assemblies is connected at a corresponding predefined location on the bottom surface of the platform;
wherein each of the strut assembly comprises:
a linear actuator configured to change the distance between the two ends along the length of the strut assembly;
a first flexure assembly at the first end of the strut assembly; and
a second flexure assembly at the second end of the strut assembly;
wherein the first and second flexure assemblies are rigid along the length of the strut assembly and flexibly bendable orthogonal to the length of the strut assembly.

9. The positioning system of claim 8 , comprising six strut assemblies arranged as a hexapod configuration to provide six degrees of freedom movement of the platform.

10. The positioning system of claim 8 , wherein each of the flexure assembly comprises a first flexure connected to a second flexure, the first flexure being flexible in a first flex direction orthogonal to the length of the strut assembly and the second flexure being flexible in a second flex direction orthogonal to the length of the strut assembly, and the first flex direction being perpendicular to the second flex direction.

11. The positioning system of claim 8 wherein each of the linear actuator is a threaded rod and stepper motor type actuator.

12. The positioning system of claim 8 , further comprising a processor configured to control each of the linear actuator.

13. The positioning system of claim 8 , wherein each of the first and second flexure assemblies comprises a monolithic body having a first location on the body that is flexible in a first flex direction orthogonal to the length of the strut assembly and a second location on the body that is flexible in a second flex direction orthogonal to the length of the strut assembly, and the first flex direction being perpendicular to the second flex direction.

Assignees

• Thorlabs Inc

Inventors

• Brooker Jeffrey S
• Ma Hongzhou
• Patton Shane
• Lieser Eric
• D'Alessio Brett

Classifications

• G01B11/272 Primary

  using photoelectric detection means · CPC title

• G02B21/06

  Means for illuminating specimens · CPC title

• G02B27/14

  operating by reflection only · CPC title

• G02B21/26

  Stages; Adjusting means therefor · CPC title

• G02B21/245

  using auxiliary sources, detectors · CPC title