Infrared refractive objective lens assembly
AssigneeDaylight Solutions, Inc.
InventorJeremy Rowlette
Life of this patent
Estimating the term…
Abstract
A mid-infrared objective lens assembly (10) includes a plurality of spaced apart, refractive lens elements (20) that operate in the mid-infrared spectral range, the plurality of lens elements (20) including an aplanatic first lens element (26) that is closest to an object (14) to be observed. The first lens element (26) has a forward surface (36) that faces the object (14) and a rearward surface (38) that faces away from the object (14). The forward surface (36) can have a radius of curvature that is negative.
Claims24
A mid-infrared objective lens assembly for gathering mid-infrared light from an object positioned at an object plane and forming the mid-infrared light at an image plane, the objective lens assembly comprising:
- a plurality of spaced apart, refractive lens elements that operate in a mid-infrared spectral range, the plurality of lens elements including an aplanatic first lens element that is closest to the object and that is positioned on an optical axis, the first lens element having a forward surface that faces the object and a rearward surface that faces away from the object;
- wherein the forward surface of the first lens element has a forward center of curvature;
- and wherein the first lens element is positioned so that the forward center of curvature is positioned on the optical axis, and is approximately at the object plane.
An assembly for analyzing an object, the assembly comprising:
- a mid-infrared objective lens assembly that gathers mid-infrared light from the object and forms the mid-infrared light at an image plane, the objective lens assembly including a plurality of spaced apart, refractive lens elements that operate in a mid-infrared spectral range, the plurality of lens elements including a first lens element that is closest to the object, the first lens element having a forward surface that faces the object and a rearward surface that faces away from the object;
- a mover assembly that moves at least one of the object and the first lens element to adjust a front separation distance between the object and the first lens element along an optical axis;
- and
- a control system that controls the mover assembly to selectively adjust the front separation distance to reduce root mean square wavefront error.
An assembly for analyzing an object, the assembly comprising:
- a stage that retains the object at an object plane;
- a mid-infrared laser that directs a laser beam that is within the mid-infrared spectral range at the object;
- a mid-infrared objective lens assembly that gathers mid-infrared light from the object and forms the mid-infrared light at an image plane, the objective lens assembly including a plurality of spaced apart, refractive lens elements that operate in a mid-infrared spectral range, the plurality of lens elements including a first lens element that is closest to the object, the first lens element having a forward surface that faces the object and a rearward surface that faces away from the object;
- a light sensing device positioned at the image plane;
- a mover assembly that moves at least one of the object and the first lens element to adjust a front separation distance between the object and the first lens element along an optical axis;
- and
- a control system that controls the mover assembly to selectively adjust the front separation distance based on a wavelength of the laser beam.
A mid-infrared, refractive objective lens assembly that gathers light in the mid-infrared spectral range from an object positioned at an object plane and focuses the light onto an image plane, the objective lens assembly having a RMS wavefront error of less than approximately 0.5 waves over a wavenumber range of approximately 5.5 micrometers in the mid-infrared spectral range and over a field of view between 100 micrometers up to 2 millimeters, the objective lens assembly having a working distance of less than one hundred millimeters.
Dependencies are inferred from the claim text.