Illumination system for object tracking
An illumination system includes a light source configured to emit an infrared light. The illumination system also includes a substrate and a plurality of light deflecting elements coupled with the substrate and configured to deflect the infrared light to illuminate an object.
1. An illumination system, comprising:
a light source configured to emit an infrared light;
a substrate; and
a plurality of light deflecting elements coupled with the substrate and configured to deflect the infrared light to illuminate an object,
wherein the substrate is a light guide, and the illumination system further includes an in-coupling element coupled with the light guide,
wherein the in-coupling element is configured to couple the infrared light emitted by the light source into the light guide to propagate inside the light guide,
wherein the plurality of light deflecting elements are coupled with the light guide at a plurality of portions of the light guide along a longitudinal direction of the light guide, and are configured to couple the infrared light propagating inside the light guide out of the light guide to illuminate the object, and
wherein the illumination system further includes a light splitting element coupled with the light guide, and configured to split the infrared light in-coupled by the in-coupling element into a plurality of infrared lights propagating toward the plurality of light deflecting elements.
2. The illumination system of claim 1 , wherein the light deflecting elements are configured to deflect the infrared light to illuminate the object, and substantially transmit a visible light.
3. The illumination system of claim 1 , wherein the light splitting element includes a plurality of one-dimensional gratings or one or more two-dimensional gratings.
4. The illumination system of claim 1 , further comprising a retardation film stacked with a light deflecting element of the plurality of light deflecting elements and configured to control a polarization of the infrared light out-coupled by the light deflecting element for illuminating the object.
5. The illumination system of claim 1 , further comprising a beam shaping element stacked with a light deflecting element of the plurality of light deflecting elements, and configured to convert the infrared light out-coupled by the light deflecting element into a structured infrared light for illuminating the object.
6. The illumination system of claim 5 , wherein the structured infrared light includes at least one of an intensity-based structured infrared light or a polarization-based structured infrared light.
7. The illumination system of claim 5 , wherein the light deflecting element and the beam shaping element are integrally formed in a single hologram.
8. The illumination system of claim 1 , wherein the light deflecting elements include at least one of a hologram optical element, a surface relief element, or a polarization volume hologram element.
9. The illumination system of claim 1 , wherein the light deflecting elements include at least one diffractive optical element.
10. The illumination system of claim 1 , wherein the light deflecting elements include at least one of a grating or an off-axis focusing lens.
11. An object tracking system, comprising:
an illumination system comprising:
a light source configured to emit an infrared light;
a substrate; and
a plurality of light deflecting elements coupled with the substrate and configured to deflect the infrared light to illuminate an object; and
an optical sensor configured to receive the infrared light reflected by the object and generate an image of the object based on the infrared light reflected by the object,
wherein the substrate is a light guide, and the illumination system further includes an in-coupling element coupled with the light guide,
wherein the in-coupling element is configured to couple the infrared light emitted by the light source into the light guide to propagate inside the light guide,
wherein the plurality of light deflecting elements are coupled with the light guide at a plurality of portions of the light guide along a longitudinal direction of the light guide, and are configured to couple the infrared light propagating inside the light guide out of the light guide to illuminate the object, and
wherein the illumination system further includes a light splitting element coupled with the light guide, and configured to split the infrared light in-coupled by the in-coupling element into a plurality of infrared lights propagating toward the plurality of light deflecting elements.
12. The object tracking system of claim 11 , further comprising:
a retardation film coupled with a light deflecting element of the plurality of light deflecting elements, and configured to control a polarization of the infrared light deflected by the light deflecting element for illuminating the object.
13. The object tracking system of claim 11 , further comprising: a beam shaping element stacked with a light deflecting element of the plurality of light deflecting elements, and configured to convert the infrared lights out-coupled by the light deflecting element into a structured infrared light for illuminating the object.
14. The object tracking system of claim 13 , wherein the structured infrared light includes at least one of an intensity-based structured infrared light or a polarization-based structured infrared light.
15. The object tracking system of claim 13 , wherein the light deflecting element and the beam shaping element are integrally formed in a single hologram.