Apparatus for generating a coherent beam illumination
An apparatus generates a coherent illumination beam. An embedded light-scattering apparatus in a transparent substrate illuminates a reflective optical element which is also embedded inside the same substrate. The reflective optical element is designed to provide a desired beam profile.
1. An apparatus comprising:
a point light source that provides light;
a light-scattering structure that scatters light from the point light source;
a light-guiding structure positioned to receive light from the point-light source and guide the light to the light-scattering structure; and
a reflective optical element configured to reflect the light from the light-scattering structure and to create a coherent light beam; and
a light-blocking unit that blocks a portion of the coherent light beam.
2. The apparatus of claim 1 , wherein the coherent light beam comprises a converging light beam.
3. The apparatus of claim 1 , wherein the coherent light beam comprises a collimated light beam.
4. The apparatus of claim 1 , wherein the reflective optical element comprises a micromirror array.
5. The apparatus of claim 1 , wherein the reflective optical element comprises a Fresnel mirror.
6. The apparatus of claim 1 , wherein the reflective optical element comprises a freeform optical reflector.
7. The apparatus of claim 1 , wherein the reflective optical element comprises a concave mirror.
8. The apparatus of claim 1 , wherein the light-blocking unit is part of the light-scattering structure.
9. The apparatus of claim 1 , wherein the point light source includes a plurality of wavelengths selected from ultraviolet (UV), red, green, blue, and infrared (IR) light sources.
10. The apparatus of claim 9 , wherein the point light source comprises an organic light emitting diode (OLED).
11. The apparatus of claim 9 , wherein the point light source comprises a red organic light emitting diode (OLED), a green OLED, and a blue OLED.
12. A near-to-eye display device, wherein the near-to-eye display device when in use is less than 25 cm from a user's eye, the near-to-eye display device comprising:
a point light source that provides light;
a light-guiding structure positioned to receive and guide the light from the point-light source;
a light-scattering structure that receives and scatters the light from the light-guiding structure;
a reflective optical element configured to reflect the light from the light-scattering structure and to create a coherent light beam, wherein the reflective optical element has a positive optical power;
a light-blocking unit that blocks a portion of the coherent light beam to form a partially blocked coherent light beam; and
a spatial light modulator mounted on the near-to-eye display device, wherein the spatial light modulator receives the partially blocked coherent light beam and forms a spatially coherent diverging light beam having a computer-generated hologram pattern.
13. The near-to-eye display device of claim 12 , wherein the light-scattering structure comprises transparent nanoparticles.
14. The near-to-eye display device of claim 12 , wherein the light-scattering structure comprises microparticles.
15. The near-to-eye display device of claim 12 , wherein the light-blocking unit is a mirror.
16. The near-to-eye display device of claim 12 , wherein the light-blocking unit is composed of a light absorbing material.
17. The near-to-eye display device of claim 12 , wherein the light-scattering structure and the reflective optical element are embedded in a transparent substrate.
18. The near-to-eye display device of claim 12 , a transparent substrate having a first face through which the coherent light beam emanates, wherein the light-scattering structure is in the substrate.
19. The near-to-eye display device of claim 12 , wherein the spatial light modulator is transmissive.
20. A method comprising:
mounting a spatial light modulator (SLM) on a near-to-eye display device, wherein the near-to-eye display device when in use is less than 25 cm from a user's eye;
guiding light from a point light source and scattering the guided light;
reflecting the scattered light to create a coherent light beam;
blocking a portion of the coherent light beam to form a partially blocked coherent beam; and
modulating the partially blocked coherent beam with the SLM.