INTEGRATED PLANAR POLARIZING DEVICE AND METHODS OF FABRICATION

• US 20100134886A1
• Filed: 12/02/2009
• Published: 06/03/2010
• Est. Priority Date: 12/02/2008
• Status: Active Grant

• Current Assignee: XI'AN Yisheng Optoelectronics Technology Co., Ltd.
• Original Assignee: Shanghai Lexvu Opto Microelectronics Technology Co., Ltd.
• Inventors: HUANG, HERB HE
• Granted Patent: US 8,422,132 B2
• Time in Patent Office: Days
• US Class Current: 359/494
• CPC Class Codes: G02B 5/3058 comprising electrically conductive elements, e.g. wire grids, conductive particles
• CPC Class Codes: H04N 9/3167 for polarizing the light beam polarizing optical systems per se G02B27/28

Abstract

The embodiments of the present invention provide an integrated planar polarizing device and methods of fabrication. The device, in the order of incidence along an optical path of an incident light beam from back position to front position, comprises a planar array of micro mirrors, a quarter wave retarder film and a reflective polarization plate. The micro mirrors are regularly spaced-apart in an identical tilted angle α relative to a base plane. The quarter wave retarder film is positioned between the micro mirrors and the reflective polarization plate. The reflective polarization plate is in parallel to the base plane and is adapted to transmit and polarize a first polarized light of the incident light beam in a first polarization state, and to reflect and polarize a second polarized light of the incident light beam in a second polarization, The micro mirrors are adapted to reflect the second polarized light passing and polarized through the quarter wave retarder film first time to pass and be polarized through the quarter wave retarder film second time, thereby converting the second polarized light to be a third polarized light in the first polarization state which can transmit the reflective polarization plate. The planar array of micro mirrors, the quarter wave retarder film and the reflective polarization plate are embedded in a transparent medium. The embodiments of the present invention could improve in device integration and simplification in assembly robustness.

Claims

1. An integrated planar polarizing device, in the order of incidence along an optical path of an incident light beam from back position to front position, comprising a planar array of micro mirrors, a quarter wave retarder film and a reflective polarization plate, wherein

the planar array of micro mirrors are regularly spaced-apart in an identical tilted angle α

relative to a base plane;

the quarter wave retarder film is positioned between the micro mirrors and the reflective polarization plate;

the reflective polarization plate is in parallel to the base plane and is adapted to transmit and polarize a first polarized light of the incident light beam in a first polarization state, and to reflect and polarize a second polarized light of the incident light beam in a second polarization;

the micro mirrors are adapted to reflect the second polarized light passing and polarized through the quarter wave retarder film first time to pass and be polarized through the quarter wave retarder film second time, thereby converting the second polarized light to be a third polarized light in the first polarization state which can transmit the reflective polarization plate; and

the planar array of micro mirrors, the quarter wave retarder film and the reflective polarization plate are embedded in a transparent medium.

2. The integrated planar polarizing device according to claim 1, wherein the reflective polarization plate is a planner polarizing wire grid array of nano-scale reflective fine strips, regularly spaced-apart in parallel to the base plane.

3. The integrated planar polarizing device according to claim 1, wherein the quarter wave retarder film is one layer of quarter wave retarder plate in parallel to the base plane, and the quarter wave retarder plate is adherently sandwiched between the reflective polarization plate and an embedded micro mirror plate, in which the micro mirrors is embedded.

4. The integrated planar polarizing device according to claim 1, wherein the quarter wave retarder film is a planner array of micro quarter wave retarders, each stacked above each of the micro mirrors, being titled at the identical tilted angle α

relative to the base plane and facing the front position; and

the micro quarter wave retarders and the micro mirrors form a planner array of micro reflective retarder plates.

5. The integrated planar polarizing device according to claim 1, further comprising a light-directing surface structure in the back position, adapted to direct an original light beam in an original incident angle ω

relative to the base plane to become the incident light beam at an incident angle relative to the base plane, wherein the incident angle is equal to the titled angle α

.

6. The integrated planar polarizing device according to claim 5, wherein the micro mirrors and the light-directing surface structure are embedded in a first transparent medium as an embedded micro mirror plate.

7. The integrated planar polarizing device according to claim 5, wherein the quarter wave retarder film is a planner array of micro quarter wave retarders, each stacked above each of the micro mirrors, being titled at the identical tilted angle α

relative to the base plane and facing the front position, and the micro quarter wave retarders and the micro mirrors form a planner array of micro reflective retarder plates; and

the micro reflective retarder plates and the light-directing surface structure are embedded in a first transparent medium as an embedded micro mirror plate.

8. The integrated planar polarizing device according to claim 5, wherein the light-directing surface structure is a light-directing prismatic surface in the back position, the light-directing prismatic surface comprises a planar array of incident-reflecting facets at a first inlet angle β

relative to the base plane continuously interleaved with incident-parallel facets in a second inlet angle γ

relative to the base plane.

9. The integrated planar polarizing device according to claim 8, wherein the incident-parallel facets are configured perpendicular to the base plane.

10. The integrated planar polarizing device according to claim 8, wherein each of the incident-parallel facets is coated with an incident-parallel antireflective film.

11. The integrated planar polarizing device according to claim 8, wherein each of the incident-reflecting facets is coated with an incident-reflecting enhancing film.

12. The integrated planar polarizing device according to claim 11, wherein the incident-reflecting enhancing film is made of any one or any combination of silver, aluminum, copper, titanium and gold.

13. The integrated planar polarizing device according to claim 5, wherein the light-directing surface structure is a complementary light-directing prismatic surface in the back position, the complementary light-directing prismatic surface comprises a planar surface array of incident-facing facets at a third inlet angle α

+90°

relative to the base plane continuously interleaved with incident-parallel facets at a second inlet angle γ

relative to the base plane, and the second inlet angle γ

is equal to the original incident angle ω and

the tilted angle α

.

14. The integrated planar polarizing device according to claim 13, wherein each of the incident-facing facets is coated with an antireflective film.

15. The integrated planar polarizing device according to claim 1, wherein further comprising a light-redirecting surface structure in the front position adapted to refract the first polarized light and the third polarized light to be transmitted out of the light-redirecting surface structure in an identical output angle λ

relative to the base plane.

16. The integrated planar polarizing device according to claim 15, wherein the reflective polarization plate and the light-redirecting surface structure are embedded in a second transparent medium as a collimating output polarizing plate.

17. The integrated planar polarizing device according to claim 15, wherein the micro mirrors are embedded in a first transparent medium as an embedded micro mirror plate, the light-redirecting surface structure is embedded in a third transparent medium as a light-redirecting plate, and the embedded micro mirror plate, the quarter wave retarder plate, the reflective polarization plate and the light-redirecting plate are adherently stacked.

18. The integrated planar polarizing device according to claim 15, wherein the light-redirecting surface structure is a light-redirecting prismatic surface in the front position, and the light-redirecting prismatic surface comprises a planar array of:

first light-redirecting prismatic facets, each in a first outlet angle θ

relative to the base plane, adapted to refract the third polarized light to the output angle λ

; and

continuously interleaved with

second light-redirecting prismatic facets, each in a second outlet angle φ

relative to the base plane, adapted to refract the first polarized light to the output angle λ

.

19. The integrated planar polarizing device according to claim 18, wherein the light-redirecting prismatic surface is configured such that the first outlet angle θ

is equal to the tilted angle α and

the second outlet angle φ

is equal to α

+90°

.

20. The integrated planar polarizing device according to claim 18, wherein the light-redirecting prismatic surface is completely coated with a light-redirecting index matching coating.

21. The integrated planar polarizing device according to claim 17, wherein a third index matching film is adherently sandwiched between the reflective polarization plate and the light-redirecting surface structure.

22. The integrated planar polarizing device according to claim 17, further comprising a first index matching film and a second index matching film, wherein the first index matching film is adherently sandwiched by the embedded micro mirror plate and the quarter wave retarder plate, and the second index matching film is adherently sandwiched by the quarter wave retarder plate and the reflective polarization plate.

23. The integrated planar polarizing device according to claim 1, wherein the transparent medium is made of silicon oxide or solid transparent polymeric materials.

24. The integrated planar polarizing device according to claim 1, wherein the micro mirrors are made of any one or any combination of silver, aluminum, copper, titanium, mercury and gold.

25. The integrated planar polarizing device according to claim 2, wherein the nano-scale reflective fine strips are made of any one or any combination of silver, copper, aluminum, titanium and gold.

26. The integrated planar polarizing device according to claim 1, wherein the titled angle α

of the micro mirrors is equal to 45°

.

27. A method of fabricating an embedded micro minor plate, wherein the method comprises:

providing a first substrate;

producing a set of first parallel symmetric V-notches into a front position of the first substrate, each of the first parallel symmetric V-notches consisting of a pair of first tilted facet and second tilted facet, and each second tilted facet being equal to a tilted angle α

relative to a base plane;

depositing a first reflective film conformally covering the first parallel symmetric V-notches on the first substrate;

lithographically patterning and selectively removing portion of the first reflective film associated with first tilted facets to form micro minors above second tilted facets;

depositing a first thick film of a transparent medium on the front position of the first substrate;

planarizing the deposited first thick film; and

detaching remaining portion of the first substrate by selectively etching, or combination of first mechanical grinding, and then selectively etching removal of the first substrate from the first thick film and the micro mirrors.

28. The method according to claim 27, before depositing the first reflective film, further comprising:

depositing a first buffer film of the transparent material above the first symmetric V-notches.

29. The method according to claim 27, wherein,

after depositing the first reflective film, the method further comprises a step of forming a quarter wave retarder film above the continuous first reflective film;

and

the step of lithographically patterning and selectively removing portion of the first reflective film comprises lithographically patterning and selectively removing portion of the first reflective film and the quarter wave retarder film associated with the first tilted facets to form micro quarter wave retarders stacked on the micro minors above the second tilted facets.

30. The method according to claim 27, further comprising:

depositing a second thick film of the transparent medium above the exposed first symmetric V-notches in a back position relative the first position;

planarizing the second thick film;

providing a second substrate;

producing a set of second parallel asymmetric V-notches into the second substrate, each of the second parallel asymmetric V-notches consisting of a set of incident-reflecting facets and incident parallel facets;

depositing a third thick film of the transparent medium above the second parallel asymmetric V-notches;

planarizing the deposited third thick film;

adhering the second substrate with the planarized third thick film bonded to the planarized second thick film in the back position; and

detaching remaining portion of the second substrate from the planarized third thick film.

31. The method according to claim 29, wherein the first substrate and/or the second substrate are made of single crystalline silicon.

32. A method of fabricating an integrated planar polarizing device, comprising the method according to claim 27, further comprising:

providing a third substrate;

producing a set of third parallel symmetric V-notches into the third substrate;

depositing a forth thick film of the transparent medium above the third parallel symmetric V-notches;

planarizing the deposited forth thick film;

depositing a second reflective film;

lithographically patterning the second reflective film by etching to form a planner polarizing wire grid array of nano-scale reflective fine strips;

depositing a fifth thick film of the transparent medium to gap fill the nano-scale reflective fine strips;

planarizing the fifth thick film;

detaching remaining portion of the third substrate from the planarized forth thick film adhered; and

adhering the collimating output polarizing plate with the forth thick film bonded to the third thick film of embedded micro minor plate.

33. A method of fabricating a collimating output polarizing plate, wherein the method comprises:

providing a third substrate;

producing a set of third parallel symmetric V-notches into the third substrate;

depositing a forth thick film of a transparent medium above the third parallel symmetric V-notches;

planarizing the deposited forth thick film;

depositing a second reflective film;

lithographically patterning the second reflective film by etching to form a planner polarizing wire grid array of nano-scale reflective fine strips;

depositing a fifth thick film of the transparent medium to gap fill the nano-scale reflective fine strips;

planarizing the fifth thick film; and

detaching remaining portion of the third substrate from the planarized forth thick film adhered.

34. The method according to claim 33, wherein the third substrate is made of single crystalline silicon.