Method for manufacturing light guide elements

• US 10,503,071 B2
• Filed: 10/26/2017
• Issued: 12/10/2019
• Est. Priority Date: 10/26/2017
• Status: Active Grant

• Current Assignee: Waymo LLC (Alphabet Inc.)
• Original Assignee: Waymo LLC (Alphabet Inc.)
• Inventors: Fidric, Bernard, Droz, Pierre-yves, Hutchison, David
• Primary Examiner(s): Young, Christopher G
• Application Number:
  US15/794,966
• Publication Number:
  US 20190129310A1
• Time in Patent Office: 775 Days
• Field of Search: 430 22, 430 30, 430312, 430313, 430315
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: G03F 7/26 Processing photosensitive materials; Apparatus therefor G03F7/12 - G03F7/24 take precedence
• CPC Class Codes: G03F 9/7003 Alignment type or strategy, e.g. leveling, global alignment

Abstract

Systems and methods described herein relate to the manufacture of optical elements and optical systems. An example method includes overlaying a first mask on a photoresist material and a substrate, and causing a light source to illuminate the photoresist material through the first mask during a first exposure so as to define a first feature. During the first exposure, the light source is positioned at a non-normal angle with respect to a plane parallel to the substrate. The method includes developing the photoresist material so as to retain an elongate portion of the photoresist material on the substrate. A first end of the elongate portion includes an angled portion that is sloped at an angle with respect to a long axis of the elongate portion. The method also includes depositing a reflective material through a second mask onto the angled portion.

Claims

1. A method comprising:

depositing a photoresist material on a substrate;

overlaying a first mask on the photoresist material, wherein the first mask defines a first feature;

causing a light source to illuminate the photoresist material through the first mask during a first exposure, wherein the light source is positioned at a first angle, wherein the first angle comprises a non-normal angle with respect to a plane parallel to the substrate;

developing the photoresist material so as to retain an elongate portion of the photoresist material on the substrate, wherein a first end of the elongate portion comprises an angled portion, and wherein the angled portion is sloped at an angle with respect to a long axis of the elongate portion;

overlaying a second mask on the developed photoresist material, wherein the second mask defines a second feature corresponding to the angled portion; and

depositing a reflective material through the second mask onto the angled portion.

2. The method of claim 1, wherein the light source is optically coupled to a collimating lens.

3. The method of claim 1, further comprising:

immersing the substrate and the photoresist material in a bath, wherein the bath comprises a liquid, wherein causing the light source to illuminate the photoresist material comprises causing the light source to illuminate the photoresist material through at least a portion of the liquid.

4. The method of claim 1, further comprising:

causing the light source to illuminate the photoresist material through the first mask during a second exposure, wherein the second exposure comprises the light source being positioned at a second angle with respect to the plane parallel to the substrate.

5. The method of claim 1, further comprising:

while causing the light source to illuminate the photoresist material through the first mask, adjusting a position of the substrate with respect to the light source.

6. The method of claim 1, further comprising:

while causing the light source to illuminate the photoresist material through the first mask, adjusting a position of the light source with respect to the substrate.

7. The method of claim 1, wherein depositing the photoresist material on the substrate comprises depositing a negative photoresist on the substrate.

8. The method of claim 1, wherein the reflective material comprises a metal that is optically-reflective in a near-infrared wavelength range.

9. The method of claim 1, wherein the elongate portion comprises a light guide manifold, wherein the method further comprise:

coupling an aperture plate to the light guide manifold, wherein the aperture plate comprises at least one aperture, wherein the at least one aperture is optically coupled to the light guide manifold.

10. The method of claim 9, wherein the aperture plate is coupled to a distal end of the light guide manifold, wherein the method further comprises:

coupling a light-emitter device to a proximal end of the light guide manifold.

11. A method comprising:

depositing a photoresist material on a substrate;

overlaying a first mask on the photoresist material, wherein the first mask defines a first feature;

overlaying a second mask on the first mask, wherein the second mask defines a second feature;

causing a light source to illuminate the photoresist material through the first mask and the second mask, wherein the light source is positioned at a first angle, wherein the first angle comprises a non-normal angle with respect to a plane parallel to the substrate;

removing the second mask;

overlaying a third mask on the first mask, wherein the third mask defines a third feature;

causing the light source to illuminate the photoresist material through the third mask and the first mask during an initial exposure;

developing the photoresist material so as to retain an elongate portion of the photoresist material on the substrate, wherein a first end of the elongate portion comprises an angled portion, and wherein the angled portion is sloped at an angle with respect to a long axis of the elongate portion;

overlaying a fourth mask on the developed photoresist material, wherein the fourth mask defines a fourth feature to correspond to the angled portion; and

depositing a reflective material through the fourth mask onto the angled portion.

12. The method of claim 11, further comprising:

causing the light source to illuminate the photoresist material through the third mask and the first mask, wherein the light source is positioned at a second angle with respect to the plane parallel to the substrate during a subsequent exposure.

13. The method of claim 11, further comprising:

while causing the light source to illuminate the photoresist material through the first mask and the second mask, adjusting a position of the substrate with respect to the light source.

14. The method of claim 11, further comprising:

while causing the light source to illuminate the photoresist material through the third mask and the first mask, adjusting a position of the substrate with respect to the light source.

15. The method of claim 11, further comprising:

while causing the light source to illuminate the photoresist material through the first mask and the second mask, adjusting a position of the light source with respect to the substrate.

16. The method of claim 11, further comprising:

while causing the light source to illuminate the photoresist material through the third mask and the first mask, adjusting a position of the light source with respect to the substrate.

17. The method of claim 11, wherein depositing the photoresist material on the substrate comprises depositing a negative photoresist on the substrate.

18. The method of claim 11, wherein the reflective material comprises a metal that is optically-reflective in a near-infrared wavelength range.

19. The method of claim 11, wherein the elongate portion comprises a light guide manifold, wherein the method further comprises:

coupling an aperture plate to the light guide manifold, wherein the aperture plate comprises at least one aperture, wherein the at least one aperture is optically coupled to the light guide manifold.

20. The method of claim 19, wherein the aperture plate is coupled to a distal end of the light guide manifold, wherein the method further comprises:

coupling a light-emitter device to a proximal end of the light guide manifold.