Broadband imaging with diffractive waveplate coated mirrors and diffractive waveplate objective lens

• US 10,436,957 B2
• Filed: 10/27/2016
• Issued: 10/08/2019
• Est. Priority Date: 10/27/2015
• Status: Active Grant

• Current Assignee: Beam Engineering For Advanced Measurements Co.
• Original Assignee: Beam Engineering For Advanced Measurements Co.
• Inventors: Tabirian, Nelson V., Liao, Zhi J., Roberts, David E.
• Primary Examiner(s): Allen, Stephone B
• Assistant Examiner(s): Dunning, Ryan S
• Application Number:
  US15/336,336
• Publication Number:
  US 20170115435A1
• Time in Patent Office: 1,076 Days
• Field of Search: 359 1- 35, 35948907, 359558-576, 359708, 359719, 359721, 359722, 359737, 359738, 359809, 359846, 359849, 359850, 359857, 359858, 359862, 359863, 359865
• CPC Class Codes: G02B 1/10 Optical coatings produced by application to, or surface treatment of, optical elements G02B1/08 takes precedence
• CPC Class Codes: G02B 13/0055 employing a special optical element
• CPC Class Codes: G02B 23/02 involving prisms or mirrors G02B23/14 takes precedence
• CPC Class Codes: G02B 27/0012 Optical design, e.g. procedures, algorithms, optimisation routines
• CPC Class Codes: G02B 27/0037 with diffracting elements G02B27/0056 takes precedence; holographic optical elements G02B5/32; zone systems G02B5/1876
• CPC Class Codes: G02B 27/4211 correcting chromatic aberrations G02B27/0056, G02B27/4222, G02B27/4227 take precedence
• CPC Class Codes: G02B 27/4261 having a diffractive element with major polarization dependent properties
• CPC Class Codes: G02B 27/4288 having uniform diffraction efficiency over a large spectral bandwidth
• CPC Class Codes: G02B 5/1833 comprising birefringent materials birefringent elements per se G02B5/3083
• CPC Class Codes: G02B 5/1842 Gratings for image generation G02B5/1847 takes precedence
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G02B 7/003 Alignment of optical elements G02B7/001, G02B7/002 take precedence; for mirrors G02B7/1822
• CPC Class Codes: G02B 7/02 for lenses supports for magnifying lenses G02B25/002
• CPC Class Codes: G02B 7/1822 comprising means for aligning the optical axis G02B7/1821 takes precedence
• CPC Class Codes: G03H 2001/0816 Iterative algorithms
• CPC Class Codes: G03H 2240/53 Diffraction efficiency [DE]

Abstract

Diffractive waveplate lenses, mirrors, devices, systems and methods for performing imaging over a broad spectral band in imaging systems, such as but not limited to astronomical imaging, surveillance imaging, and in communication systems, such as laser communication systems. Corrector mirrors are used with a flat diffractive wave diffractive waveplate lens so that chromatic aberrations of the diffractive waveplate lens are reduced with the imaging system.

Claims

1. A method for fabricating an imaging system with diffractive waveplate coated mirrors correcting chromatic aberrations of a diffractive waveplate objective lens in an imaging system, comprising the steps of:

selecting a diameter and focal length of the diffractive waveplate objective lens;

selecting axial apex spacings and the diameters of the diffractive waveplate coated mirrors so that there is no vignetting for either of the diffractive waveplate coated mirrors for an entire operating wavelength range;

selecting polynomial expansion coefficients for both curvature and phase profile of a first diffractive waveplate coatings of a first diffractive waveplate coated mirror so that an objective diffractive waveplate lens is imaged onto a surface of a second diffractive waveplate coated mirror at all wavelengths within an operating bandwidth of the imaging system for paraxial rays;

setting polynomial expansion coefficients for both curvature and phase profile of a second diffractive waveplate coating of a second diffractive waveplate coated mirror, by having an imaging system focal point be at a selected distance from an apex of the second mirror, and that all wavelengths within the operating band converge to the imaging system focal point for paraxial rays; and

adjusting the polynomial expansion coefficients for the curvatures and phase profiles of the first and second diffractive waveplate coated mirrors in order to bring all rays incident over an entire clear aperture of the objective lens to the same imaging system focal point.

2. The method of claim 1 wherein the imaging system is a telescope.

3. The method of claim 1 wherein the imaging system is augmented reality glasses.

4. The method of claim 1 wherein the imaging system is a binocular.

5. The method of claim 1, further comprising the steps of:

providing a light source;

providing a beam shaping system for forming an illuminated area;

and

providing an imaging sensor in the focal point of the imaging system.

6. The method of claim 5 wherein said light source emits radiation at wavelengths within a spectral band selected from at least one of ultraviolet, visible, near infrared, short wave infrared, mid-wave infrared and long-wave infrared wavelengths.

7. The method of claim 5 wherein said light source is a laser, which emits radiation at wavelengths within the spectral band of the imaging sensor, selected from at least one of ultraviolet, visible, near infrared, short wave infrared, mid-wave infrared, and long-wave infrared wavelengths.

8. The method of claim 7 wherein said imaging sensor includes:

a camera for collecting imaging data of the object within a spectral band selected from at least one of ultraviolet, visible, near infrared, short wave infrared, mid-wave infrared, and long-wave infrared wavelengths, wherein the camera captures imaging data when signals emitted by the laser light source of and reflected by the imaged object or scene are collected by said camera.

9. The method of claim 5 wherein said beam shaping system comprises:

diffractive waveplate optics.

10. The method of claim 9 wherein said diffractive waveplate optics is electrically switched between states with and without optical power producing variable beam divergence or variable beam profile.

11. The method of claim 1, wherein both of said diffractive waveplate objective lens and said diffractive waveplate coated mirrors operate in a broad band of spectrum selected from at least one of:

ultraviolet, visible, near infrared, short wave infrared, mid-wave infrared, and long-wave infrared wavelengths.

12. The method of claim 1, wherein both of said diffractive waveplate objective lens and said diffractive waveplate coated mirrors operate in multiple spectral bands selected from at least one of:

ultraviolet, visible, near infrared, short wave infrared, mid-wave infrared, and long-wave infrared wavelengths.

13. The method of claim 1, wherein the diffractive waveplate coated mirrors further comprise

a phase retardation layer conforming to the reflective surface.

14. The method of claim 13, wherein said phase retardation layer is a quarter-wave plate.