Waveguide structure and outcoupling elements

1. A head mounted device comprising:

a frame;

a near-infrared light source coupled with the frame, wherein the near-infrared light source is configured to emit near-infrared light; and

an optical element secured to the frame, the optical element including:

a transparent layer;

a plurality of outcoupling elements distributed across the transparent layer; and

a transparent waveguide structure configured to receive the near-infrared light from the near-infrared light source coupled with the frame, wherein the transparent waveguide structure is configured to deliver the near-infrared light from the near-infrared light source to the outcoupling elements, and wherein the outcoupling elements are configured to outcouple the near-infrared light as near-infrared illumination light to illuminate an eye region with patterned near-infrared illumination light, the outcoupling elements including a grating configured to receive the near-infrared light from the transparent waveguide, wherein the outcoupling elements further include a diffractive optical element (DOE), and wherein the grating is configured to receive the near-infrared light and illuminate the DOE.

2. The head mounted device of claim 1 , wherein the DOE is configured to control a divergence and a direction of the near-infrared illumination light.

3. The head mounted device of claim 1 , wherein the DOE includes a metasurface.

4. An optical system comprising:

a non-visible light source configured to emit non-visible light;

a transparent layer;

outcoupling elements positioned across the transparent layer; and

a waveguide structure configured to deliver the non-visible light from the non-visible light source to the outcoupling elements, wherein the outcoupling elements are configured to outcouple the non-visible light as non-visible illumination light, and wherein the outcoupling elements include a curved mirror and a refractive microlens configured to provide beam shaping for the non-visible illumination light, wherein the curved mirror directs the non-visible light through the refractive microlens.

5. The optical system of claim 4 , wherein a first outcoupling element of the outcoupling elements is configured to outcouple the non-visible illumination light as a first light cone having a first divergence angle, and wherein a second outcoupling element of the outcoupling elements is configured to outcouple the non-visible illumination light as a second light cone having a second divergence angle that is different than the first divergence angle.

6. The optical system of claim 4 , wherein the waveguide structure includes a transparent dielectric material to confine the non-visible light to the waveguide structure.

7. The optical system of claim 4 , wherein a material used for the waveguide structure is transparent to visible light.

8. The optical system of claim 4 , wherein the waveguide structure is coupled between the non-visible light source and at least a portion of the outcoupling elements.

9. The optical system of claim 8 , wherein the waveguide structure follows an indirect curving path between the non-visible light source and the outcoupling elements.

10. The optical system of claim 4 , wherein the non-visible light source includes at least one of a laser source, a superluminescent light emitting diode (S-LED), a vertical-cavity surface-emitting laser (VCSEL), or an integrated laser array.

11. The optical system of claim 4 , wherein the outcoupling elements are less than 75 microns at a widest or longest dimension.

12. The optical system of claim 4 , wherein the outcoupling elements are in a field of view (FOV) of an eye of a user of the optical system.

13. The optical system of claim 4 further comprising:

an input coupling structure configured to receive the non-visible light from the non-visible light source and inject the non-visible light into the waveguide structure.

14. The optical system of claim 4 further comprising:

an input coupler configured to incouple the non-visible light emitted by the non-visible light source into the waveguide structure.

15. An optical system comprising:

a non-visible light source configured to emit non-visible light;

a transparent layer;

outcoupling elements positioned across the transparent layer; and

a waveguide structure configured to deliver the non-visible light from the non-visible light source to the outcoupling elements, wherein the outcoupling elements are configured to outcouple the non-visible light as non-visible illumination light, and wherein the outcoupling elements include a curved mirror and a refractive microlens configured to provide beam shaping for the non-visible illumination light, wherein the outcoupling elements further include a microlens, and wherein the grating is configured to receive the near-infrared light and illuminate the microlens.

16. The optical system of claim 15 , wherein the outcoupling elements further include a microlens, and wherein the grating is configured to receive the near-infrared light and illuminate the microlens.

17. The optical system of claim 15 , wherein the microlens is configured to control a divergence and a direction of the near-infrared illumination light.

18. The optical system of claim 15 , wherein the microlens includes a dielectric material.

19. The optical system of claim 15 , wherein the outcoupling elements are less than 75 microns at a widest or longest dimension.