US 12,001,088 B2
Optical elements for integrated IR and visible camera for depth sensing and systems incorporating the same
Steven John Robbins, Redmond, WA (US); and Michael James Escuti, Raleigh, NC (US)
Assigned to META PLATFORMS TECHNOLOGIES, LLC, Menlo Park, CA (US)
Filed by Meta Platforms Technologies, LLC, Menlo Park, CA (US)
Filed on Feb. 12, 2021, as Appl. No. 17/174,714.
Claims priority of provisional application 62/975,692, filed on Feb. 12, 2020.
Claims priority of provisional application 62/975,685, filed on Feb. 12, 2020.
Prior Publication US 2021/0247632 A1, Aug. 12, 2021
Int. Cl. G02F 1/01 (2006.01); G02F 1/1335 (2006.01); G02F 1/137 (2006.01); H04N 23/11 (2023.01)
CPC G02F 1/0136 (2013.01) [G02F 1/133504 (2013.01); G02F 1/133536 (2013.01); G02F 1/137 (2013.01); H04N 23/11 (2023.01); G02F 2203/01 (2013.01); G02F 2203/07 (2013.01); G02F 2203/11 (2013.01)] 36 Claims
OG exemplary drawing
 
1. A multi-spectral optical imaging device, comprising:
a switchable element configured to be switched between first and second states, wherein one of the first and second states alters a polarization of light; and
a geometric phase element arranged to receive the light from the switchable element, wherein the geometric phase element is configured to diffract a first wavelength band of the light to alter a direction of propagation thereof based on the polarization and without substantially altering a direction of propagation of a second wavelength band of the light, responsive to the first state of the switchable element.
 
26. An optical shutter, comprising:
a first reflective Bragg polarization grating;
a liquid crystal layer on the first reflective Bragg polarization grating; and
a second reflective Bragg polarization grating on the liquid crystal layer,
wherein the liquid crystal layer is configured to be switched between first and second states, wherein one of the first and second states alters a polarization of light, and
wherein the first and second reflective Bragg polarization gratings are respectively configured to diffract a first polarization of a first wavelength band of the light into a reflective first-order direction and to transmit a second polarization of the first wavelength band of the light into a zero-order direction without substantially altering a direction of propagation of a second wavelength band of the light.
 
32. A multi-spectral optical imaging detector, comprising:
a camera comprising an image sensor that is configured to detect first and second wavelength bands of light; and
an optical shutter comprising a switchable liquid crystal layer and a geometric phase element configured to selectively transmit or diffract the first wavelength band of the light towards or away from the image sensor, respectively, based on a polarization thereof, and to transmit the second wavelength band of the light to the image sensor independent of the polarization thereof.