Methods of diffractive lens and mirror fabrication

• US 10,197,715 B1
• Filed: 06/30/2016
• Issued: 02/05/2019
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: U.S. Government
• Original Assignee: Beam Engineering For Advanced Measurements Co., The United States Of America As Represented By The Secretary Of The Army
• Inventors: Tabirian, Nelson V., Serak, Svetlana V., Steeves, Diane M., Kimball, Brian R., Roberts, David E.
• Primary Examiner(s): Burkhart, Elizabeth A
• Application Number:
  US15/198,026
• Time in Patent Office: 950 Days
• Field of Search: 427162
• CPC Class Codes: B29D 11/00269 Fresnel lenses
• CPC Class Codes: B29D 11/00355 with a refractive index gradient
• CPC Class Codes: B29D 11/00432 Auxiliary operations, e.g. machines for filling the moulds B29D11/00125 takes precedence
• CPC Class Codes: B29D 11/00769 Producing diffraction gratings
• CPC Class Codes: G02B 5/1857 using exposure or etching means, e.g. holography, photolithography, exposure to electron or ion beams
• CPC Class Codes: G02B 5/1866 Transmission gratings characterised by their structure, e.g. step profile, contours of substrate or grooves, pitch variations, materials G02B5/1809, G02B5/1828, G02B5/1833, G02B5/1838 and G02B5/1847 take precedence

Abstract

Methods of fabricating optical lenses and mirrors, systems and composite structures based on diffractive waveplates, and fields of application of said lenses and mirrors that include imaging systems, astronomy, displays, polarizers, optical communication and other areas of laser and photonics technology. Diffractive lenses and mirrors of shorter focal length and larger size, with more closely spaced grating lines, and with more exacting tolerances on the optical characteristics, can be fabricated than could be fabricated by previous methods.

Claims

1. A method of replicating a diffractive waveplate lens so that a replicated optical component size is the same as the diffractive waveplate lens from which it is replicated, and the replicated optical component focal length is half of the diffractive waveplate lens from which it is replicated, comprising the steps of:

providing a collimated linearly polarized laser beam;

arranging a diffractive waveplate lens in the path of the beam;

producing a substrate coated with a photoalignment layer;

placing the substrate in proximity to the diffractive waveplate lens; and

exposing the substrate to the laser beam propagated through the diffractive waveplate lens to produce a photoalignment pattern of optical anisotropy axis orientation in the photoalignment layer.

2. The method of claim 1 further comprising the step of deposing at least one layer of a liquid crystal polymer film on the substrate having a thickness approximately half a minimum feature size in the photoalignment pattern.