US 12,007,655 B2
Optical attenuation via switchable grating
Bernard Charles Kress, Redwood City, CA (US); and Ashley N Saulsbury, Bellevue, WA (US)
Assigned to Microsoft Technology Licensing, LLC, Redmond, WA (US)
Filed by Microsoft Technology Licensing, LLC, Redmond, WA (US)
Filed on May 25, 2021, as Appl. No. 17/330,161.
Prior Publication US 2022/0382054 A1, Dec. 1, 2022
Int. Cl. G02B 27/01 (2006.01); G02F 1/1334 (2006.01); G02F 1/1347 (2006.01); G02F 1/29 (2006.01)
CPC G02F 1/1347 (2013.01) [G02B 27/0172 (2013.01); G02F 1/13342 (2013.01); G02F 1/292 (2013.01); G02B 27/0101 (2013.01)] 19 Claims
OG exemplary drawing
 
1. An optical attenuator, comprising:
a first switchable grating configured to diffract light within a red wavelength band at a first diffraction angle;
a second switchable grating configured to diffract light within a green wavelength band at a second diffraction angle;
a third switchable grating configured to diffract light within a blue wavelength band at a third diffraction angle;
a first electrode pair configured to apply a voltage across the first switchable grating to tune a first proportion of incident light diffracted at the first diffraction angle;
a second electrode pair configured to apply a voltage across the second switchable grating to tune a second proportion of incident light diffracted at the second diffraction angle;
a third electrode pair configured to apply a voltage across the second switchable grating to tune a third proportion of incident light diffracted at the third diffraction angle; and
an optical dump, wherein the optical attenuator is configured to perform color correction by diffracting at least the first proportion of incident light and the second proportion of the incident light to the optical dump, the second proportion different than the first proportion.