VIRTUAL IMAGE PHASE ARRAY

• US 20150316764A1
• Filed: 05/05/2015
• Published: 11/05/2015
• Est. Priority Date: 05/05/2014
• Status: Active Grant

• Current Assignee: LightMachinery, Inc.
• Original Assignee: LightMachinery, Inc.
• Inventors: Hunter, John H., MILLER, Ian J., BOISCLAIR, Shane, WILLIAMS, Edward S., WIMPERIS, Chris, ZASTERA, Vaz
• Granted Patent: US 10,162,186 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 1/11 Anti-reflection coatings
• CPC Class Codes: G02B 27/0087 Phased arrays
• CPC Class Codes: G02B 27/144 using partially transparent surfaces without spectral selectivity G02B27/147 takes precedence
• CPC Class Codes: G02B 27/4205 having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant
• CPC Class Codes: G02B 6/29358 Multiple beam interferometer external to a light guide, e.g. Fabry-Pérot, etalon, VIPA plate, OTDL plate, continuous interferometer, parallel plate resonator G02B6/29347, G02B6/29349, G02B6/2935, G02B6/29361 take precedence; resonator evanescently coupled to light guide G02B6/29335

Abstract

A virtual image phase array (VIPA) includes two parallel surfaces, a first highly-reflective surface with a highly-reflective coating, and a second partially-reflective surface. The first highly-reflective surface also requires an input zone with an anti-reflection coating, which abuts the highly-reflective coating, with a transition zone therebetween. Light enters the VIPA through the input zone, and reflects back and forth between the highly and partially reflective surfaces, gradually leaking out through the partially reflective surface. To minimize the transition zone and thereby minimize the input angle of incidence and maximize the number of reflections per unit of length, the substrate coated with the highly-reflective coating is subsequently polished at an acute angle resulting in the transition zone having the same sharp angle.

Claims

14. A method of fabricating a virtual image phase array (VIPA) comprising:

providing a first support substrate with a first surface and an end;

providing a first reflective coating on the first surface of the first support substrate;

providing a second reflective coating substantially parallel to the first reflective coating with a gap therebetween;

polishing the end of the first support substrate at an acute angle forming a beveled edge of the first support substrate and the first reflective coating, thereby forming a narrow bevelled transition region at the beveled edge of the first reflective coating between the first reflective coating and the beveled edge of the first support substrate.

1. A virtual image phase array (VIPA) comprising:

a transparent support substrate;

a first reflective coating on a first reflective surface of the transparent support substrate;

a second reflective surface separated by a gap from the first reflective coating;

wherein the transparent support substrate and the first reflective coating include a beveled edge at an acute angle from the second reflective surface forming a narrow bevelled transition region at the edge of the first reflective coating between the first reflective coating and the beveled edge of the support substrate.

2. The VIPA according to claim 1, wherein the beveled edge is at between 40°

and 50°

, from the second reflective surface.

3. The VIPA according to claim 1, further comprising an input port capable of directing light through the beveled edge of the transparent support substrate onto the second reflective surface at an angle of incidence of less than 1°

, while avoiding the transition region during input and reflection.

4. The VIPA according to claim 1, wherein a width of the transition region is between 0.5 times to 2.0 times a thickness of the first reflective coating.

5. The VIPA according to claim 1, wherein a width of the transition region is less than 10 μ

m.

6. The VIPA according to claim 1, further comprising an additional section of transparent material, including a first beveled surface, mounted on the beveled edge of the transparent support substrate, and a second surface at an acute angle to the first surface forming an input surface for light.

7. The VIPA according to claim 6, wherein the input surface and the first reflective surface of the transparent support substrate are substantially co-planar meeting at the transition region.

8. The VIPA according to claim 6, wherein the input surface is offset from the first reflective coating, whereby the input surface overlaps the transition region to protect the transition region.

9. The VIPA according to claim 6, further comprising a mounting substrate mounted on the first reflective coating to protect the first reflective coating.

10. The VIPA according to claim 9, wherein an upper surface of the mounting substrate is co-planar with the input surface to facilitate coating thereof together.

11. The VIPA according to claim 1, further comprising a mounting substrate mounted on the first reflective coating including a beveled edge coplanar with the beveled edge of the transparent support substrate.

12. The VIPA according to claim 1, further comprising an additional support substrate including the second reflective surface with a second reflective coating, which is separated from the first-reflective coating by an air gap.

13. The VIPA according to claim 12, wherein the beveled edge of the transparent support substrate faces downwardly toward the second reflective surface, whereby light launched through the a second surface of the transparent support substrate, opposite the first reflective surface, travels through the beveled edge of the transparent support substrate into the air gap, and diffracts towards the second reflective surface at an angle of incidence of less than 5°

.

15. The method according to claim 14, wherein the polishing step includes polishing the transition region to a width of between one half of the thickness of the first reflective coating to twice the thickness of the first reflective coating.

16. The VIPA according to claim 14, wherein the polishing step includes polishing the transition region to a width of less than 10 um.

17. The method according to claim 14, wherein the polishing step includes polishing the beveled edge to an acute angle of between 40°

and 50°

.

18. The method according to claim 14, further comprising:

mounting a first surface of an additional matching section of transparent material on the beveled edge of the first support substrate, whereby a second surface of the additional matching section forms an input surface that is substantially coplanar or parallel to the first surface of the first support substrate.

19. The method according to claim 14, wherein the steps of providing the first and second reflective coatings comprise deposited the first and second reflective coatings on opposite sides of the first support substrate.

21. The method according to claim 14, further comprising:

mounting a mounting substrate on the first reflective coating before the polishing step; and

wherein the polishing step comprises polishing both the end of the first support substrate and an end of the mounting substrate, thereby forming the beveled edge of the first reflective coating.

22. The method according to claim 21, further comprising:

connecting a first surface of an additional matching section of transparent material to the ends of the first support substrate and the mounting substrate; and

simultaneously polishing an upper surface of the mounting substrate and a second surface of the matching section;

whereby the second surface of the matching section forms an input surface that is substantially parallel to the first and second reflective coatings.

23. The method according to claim 14, further comprising providing a second support substrate on which the partially-reflective coating is deposited, whereby the gap is an air gap between the first and second support substrates.