Waveguide with a three-dimensional lens

• US 20050271326A1
• Filed: 06/04/2004
• Published: 12/08/2005
• Est. Priority Date: 06/04/2004
• Status: Active Grant

• Current Assignee: POA Sana Liquidating Trust
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Luo, Xiao Bing
• Granted Patent: US 7,676,131 B2
• Time in Patent Office: Days
• US Class Current: 385/43
• CPC Class Codes: G02B 2006/12102 Lens
• CPC Class Codes: G02B 2006/1219 Polymerisation
• CPC Class Codes: G02B 6/12004 Combinations of two or more optical elements
• CPC Class Codes: G02B 6/1221 made from organic materials
• CPC Class Codes: G02B 6/1228 Tapered waveguides, e.g. integrated spot-size transformers for coupling with fibres G02B6/305
• CPC Class Codes: G02B 6/32 having lens focusing means positioned between opposed fibre ends with lens being an integral part of the single fibre end G02B6/262
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

Optical transmission structures include a waveguide and an optical lens wherein the optical lens has a sufficiently large thickness to allow the formation of a curved front lens surface that collimates transmitted light rays so that they travel within a plane that is coplanar to a working surface. The present invention also relates to a technique for manufacturing the optical transmission structure, which involves the use of a photopolymer material. The optical transmission structure can be implemented in various systems such as a system for optical data input.

Claims

1. An apparatus comprising:

a support substrate having a top surface;

a waveguide suitable for transmitting light, the waveguide being formed upon the top surface of the support substrate and having a waveguide thickness that is measured in the orthogonal direction from the top surface of the support substrate; and

an optical lens that is integrally formed with the waveguide, the optical lens having a maximum lens thickness that is greater than the waveguide thickness, wherein light rays transmitted from the waveguide are collimated by the optical lens so that the light rays are emitted out of the optical lens in a plane that is substantially coplanar to the top surface of the support substrate.

2. An apparatus as recited in claim 1 wherein the optical lens has a front surface through which light rays are transmitted and/or received, the front surface having at least an in-plane collimating lens curve that has an outline that is defined within a plane that is perpendicular to the top surface of the support substrate and which is aligned with the direction that a particular light ray travels.

3. An apparatus as recited in claim 1 further comprising:

at least one side surface of the optical lens, wherein the side surface and the in-plane collimating lens curve rise upwards and only bend inwards and towards an apex of the optical lens, the apex being at a maximum height point of the optical lens.

4. An apparatus as recited in claim 1 wherein the optical lens has an inclined back surface that has a first edge that joins the waveguide and a second edge that extends to the height of a maximum lens thickness of the optical lens.

5. An apparatus as recited in claim 4 wherein the inclined back surface is substantially flat.

6. An apparatus as recited in claim 2 wherein the optical lens has a width that expands as the optical lens extends away from the waveguide.

7. An apparatus as recited in claim 2 wherein the front surface of the optical lens has a directionally collimating lens curve that has an outline defined within a plane that is substantially coplanar with the top surface of the support substrate, wherein the directionally collimating lens curve collimates the light rays such that substantially all of the light rays are emitted out of the optical lens to be parallel to each other and to travel in a single direction.

8. An apparatus as recited in claim 7 wherein the optical lens forms a tear drop outline shape upon the top surface of the support substrate.

9. An apparatus as recited in claim 1 wherein the waveguide is an elongated structure that is connected to a light source or light detector.

10. An apparatus as recited in claim 1 wherein the support substrate is a bottom cladding material layer.

11. An apparatus as recited in claim 1 further comprising:

a bottom cladding material layer that is formed between the support substrate and each of the waveguide and the optical lens.

12. An apparatus as recited in claim 1 further comprising:

a top cladding material layer that covers the waveguide.

13. An optical device comprising:

a support substrate having a top surface;

a bottom cladding layer formed on the top surface of the support substrate;

a waveguide suitable for transmitting light, the waveguide being formed upon the bottom cladding layer; and

an optical lens having a first end that is connected to the waveguide such that light rays can be communicated between the waveguide and the optical lens, the optical lens also having a second end that forms a front lens surface, the optical lens having a raised region in between the first and second end, wherein the optical lens collimates the light rays such that the light rays transmitted through the front lens surface travel are parallel with the top surface of the support substrate.

14. An apparatus as recited in claim 13 further comprising:

at least one side surface of the optical lens, wherein the side surface and the front lens surface rise upwards and only bend inwards and towards an apex of the optical lens, the apex being at a maximum height point of the optical lens

15. An optical device as recited in claim 13 wherein the light rays transmitted through the front lens surface of the optical lens also travel substantially within a plane that is coplanar with the top surface of the support substrate.

16. An optical device as recited in claim 13 wherein the raised region of the optical lens has a height that is taller than a height of the waveguide.

17. An optical device as recited in claim 13 wherein the front lens surface is curved and extends up to the raised region of the optical lens.

18. An optical device as recited in claim 13 wherein the optical lens has an inclined back surface that has a first edge that connects to the waveguide and a second edge that extends to raised region of the optical lens.

19. An optical device as recited in claim 13 wherein the optical lens has a width that expands as the optical lens extends away from the waveguide.

20. An optical device as recited in claim 17 wherein the front surface of the optical lens is also curved in order to collimate the light rays such that substantially all of the light rays that are emitted out of the optical lens are parallel to each other and travel in a single direction.

21. An apparatus as recited in claim 13 further comprising:

a top cladding layer that covers the waveguide.

22. An apparatus as recited in claim 21 wherein the inclined back surface is inclined at an angle equal to at least sin⁻

1({square root}{square root over (n₁²−

n₂²)}/n₃), wherein n₁ is the index of refraction of the waveguide, n₂ is the index of refraction of the top or bottom cladding layer, whichever is larger, and n₃ is the index of refraction of the optical lens.

23. An optical data input system comprising:

a support substrate having a top surface;

a bottom cladding layer formed on the top surface of the support substrate;

a lamina of light formed over the top surface of the support substrate;

a plurality of optical structures that are each formed of a waveguide and an optical lens, each of the waveguides being suitable for transmitting light in order to form the lamina of light, each of the optical structures being formed upon the bottom cladding layer, each of the optical lenses having a first end that is connected to a respective waveguide such that light rays can be communicated between the waveguide and the optical lens, each of the optical lenses also having a second end that forms a front lens surface, each of the optical lenses having a raised region in between their respective first and second ends, wherein each of the optical lenses collimates the light rays from a respective waveguide such that the light rays transmitted through the front lens surface travel within a plane that is substantially coplanar to the top surface of the support substrate; and

an optical position detection device that is optically coupled to each of the waveguides and configured to detect data entries to the input system by determining the location of interrupts in the lamina caused when data is entered to the input system.

24. A system as recited in claim 23 wherein light rays transmitted by each optical structure of a first set of optical structures travels substantially along a first axis and are received by respective optical structures of a second set of optical structures.

25. A system as recited in claim 24 wherein light rays transmitted by each optical structure of a third set of optical structures travels substantially along a second axis and are received by respective optical structures of a fourth set of optical structures, wherein the first axis and the second axis are substantially perpendicular to each other.

26. A system as recited in claim 24 wherein the raised region of each of the optical lens has a height that is taller than a height of the waveguides.

27. A system as recited in claim 26 wherein the front lens surface of each of the optical lenses has an in-plane collimating lens curve that has an outline that is defined within a plane that is perpendicular to the top surface of the support substrate and which is aligned with the direction that a particular light ray travels.

28. A system as recited in claim 26 wherein the front lens surface of each optical lens is curved and extends up to the raised region of each optical lens.

29. A system as recited in claim 28 wherein the front surface of each optical lens is also curved in order to collimate the light rays such that substantially all of the light rays are emitted out of each optical lens in a single direction.