OPTICAL DESIGNS FOR ZERO ORDER REDUCTION

• US 20110075259A1
• Filed: 11/30/2010
• Published: 03/31/2011
• Est. Priority Date: 01/21/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: PrimeSense Ltd (Apple Inc.)
• Inventors: Shpunt, Alexander
• Granted Patent: US 8,630,039 B2
• Time in Patent Office: Days
• US Class Current: 359/566
• CPC Class Codes: G02B 27/0944 Diffractive optical elements, e.g. gratings, holograms gratings per se G02B5/18; holograms used as optical elements per se G02B5/32
• CPC Class Codes: G02B 27/4233 having a diffractive element [DOE] contributing to a non-imaging application diffusers having a diffractive element G02B5/0252; filters having a diffractive element G02B5/203; systems for controlling the direction of light having diffractive elements G02B26/0808; scanning systems having diffractive elements G02B26/106; beam shaping systems using diffractive optical elements G02B27/0944; beam splitting or combining systems operating by diffraction G02B27/1086
• CPC Class Codes: G02B 27/425 in illumination systems mask illumination systems in photolithographic systems G03F7/70158
• CPC Class Codes: G02B 27/4266 Diffraction theory; Mathematical models
• CPC Class Codes: G02B 27/4272 having plural diffractive elements positioned sequentially along the optical path
• CPC Class Codes: G02B 27/4277 being separated by an air space
• CPC Class Codes: G03B 35/00 Stereoscopic photography

Abstract

Apparatus for projecting a pattern includes a first diffractive optical element (DOE) configured to diffract an input beam so as to generate a first diffraction pattern on a first region of a surface, the first diffraction pattern including a zero order beam. A second DOE is configured to diffract the zero order beam so as to generate a second diffraction pattern on a second region of the surface such that the first and the second regions together at least partially cover the surface.

Claims

1. Apparatus for projecting a pattern, comprising:

a first diffractive optical element (DOE) configured to diffract an input beam so as to generate a first diffraction pattern on a first region of a surface, the first diffraction pattern comprising a zero order beam; and

a second DOE configured to diffract the zero order beam so as to generate a second diffraction pattern on a second region of the surface such that the first and the second regions together at least partially cover the surface.

2. The apparatus according to claim 1, wherein the second DOE comprises an optically active region configured to receive the zero order beam, and an optically inactive region configured to transmit the first diffraction pattern absent the zero order beam.

3. The apparatus according to claim 1, wherein the first and the second DOEs are formed on one optical element.

4. The apparatus according to claim 1, wherein the first and the second DOEs are formed on separate optical elements.

5. The apparatus according to claim 1, wherein the second diffraction pattern comprises a further zero order beam, and wherein an energy flux of the further zero order beam is less than 0.1% of an energy flux of the input beam.

6. The apparatus according to claim 1, wherein the input beam has an input beam wavelength, and wherein the first DOE and the second DOE are configured so that the first and the second regions at least partially cover the surface independently of the input beam wavelength.

7. The apparatus according to claim 1, wherein the first diffraction pattern forms a first diffraction image comprising a first set of first spots on the first region, and wherein the second diffraction pattern forms a second diffraction image comprising a second set of second spots on the second region.

8. The apparatus according to claim 1, wherein at least one of the first and the second diffraction patterns forms a diffraction image comprising at least one of a set of lines and an area having graduated intensities.

9. The apparatus according to claim 1, wherein the first region and the second region tile the surface.

10. The apparatus according to claim 1, wherein the first region is bounded by a first rectangle and a second rectangle smaller than the first rectangle, the first and the second rectangles having a common center, and wherein the second region is bounded by the second rectangle.

11-20. -20. (canceled)

21. A method for projecting a pattern, comprising:

diffracting an input beam with a first diffractive optical element (DOE) so as to generate a first diffraction pattern on a first region of a surface, the first diffraction pattern comprising a zero order beam; and

diffracting the zero order beam with a second DOE so as to generate a second diffraction pattern on a second region of the surface such that the first and the second regions together at least partially cover the surface.

22-23. -23. (canceled)