Optical attenuation via switchable grating
AssigneeMicrosoft Technology Licensing, LLC
InventorsBernard Charles Kress, Ashley N Saulsbury
Life of this patent
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Abstract
Examples are disclosed relating to tunable attenuation of incident light using a switchable grating. One example provides an optical attenuator comprising a switchable grating configured to diffract light within a wavelength band at a diffraction angle. The optical attenuator further comprises an electrode pair configured to apply a voltage across the switchable grating to tune a proportion of incident light diffracted at the diffraction angle, and an optical dump to receive the proportion of incident light diffracted.
Claims19
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.
A method for attenuating light, the method comprising:
- receiving incident light at a first switchable grating configured to diffract light within a first wavelength band at a first diffraction angle with a voltage-dependent diffraction efficiency;
- applying a voltage across the first switchable grating to tune a first proportion of incident light within the first wavelength band diffracted at the first diffraction angle;
- diffracting the first proportion of the incident light within the first wavelength band at the first diffraction angle to an optical dump;
- receiving incident light at a second switchable grating with a voltage-dependent diffraction efficiency configured to diffract light within a second wavelength band at a second diffraction angle, the second wavelength band comprising a different color light than the first wavelength band;
- applying a voltage across a second switchable grating to tune a second proportion of incident light within a second wavelength band diffracted at a second diffraction angle;
- and
- perform color correction by diffracting the second proportion of the incident light within the second wavelength band to the optical dump, the second proportion different than the first proportion.
An optical device, comprising:
- a plurality of switchable gratings configured to diffract incident light at a diffraction angle, each switchable grating of the plurality of switchable gratings configured to diffract light at a corresponding wavelength band;
- and
- a controller configured to, for each switchable grating, control the switchable grating to, based on a voltage applied across the switchable grating, perform color correction by tuning a proportion of the incident light at the respective wavelength band that is diffracted.
Dependencies are inferred from the claim text.