Polarizer

• US 6,977,774 B1
• Filed: 08/09/1999
• Issued: 12/20/2005
• Est. Priority Date: 08/07/1998
• Status: Expired due to Term

• Current Assignee: Autocloning Technology Limited
• Original Assignee: Autocloning Technology Limited
• Inventors: Kawashima, Takayuki, Otera, Yasuo, Kawakami, Shojiro
• Primary Examiner(s): Boutsikaris, Leonidas
• Application Number:
  US09/762,497
• Time in Patent Office: 2,325 Days
• Field of Search: 359/485, 359/638, 359487-490, 359/495, 359/530, 359/589, 359/497, 359/500
• US Class Current: 359/485.03
• CPC Class Codes: G02B 1/005 made of photonic crystals or photonic band gap materials photonic band-gap structures or photonic lattices in integrated optics G02B6/1225; photonic band-gap structures or photonic lattices in optical fibres G02B6/02295
• CPC Class Codes: G02B 5/1809 with pitch less than or comparable to the wavelength
• CPC Class Codes: G02B 5/3025 Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state G02B5/3008, G02B5/3016 take precedence
• CPC Class Codes: G02B 5/3033 in the form of a thin sheet or foil, e.g. Polaroid

Abstract

A polarizer which has and regularly arranged two-dimensional structure which has a pitch of 1 mm or so or less. The polarizer has structure in which two or more film-shaped materials which have a substantially regularly arranged one-dimensional undulation. The polarizer also has a substantially regularly arranged two-dimensional structure. For example, the polarizer consist of materials 1 and 2 which have different refractive indexes. A regularly arranged two-dimensional structure which has a pitch of 1 mm or less can be obtained by a simple method. Because of this structure, the polarizer transmits the incident light which has a specific polarized plane and reflects the incident light which has a polarized plane which is orthogonal to the plane.

Claims

1. A polarizer comprising:

a multilayered structure having two or more transparent layers disposed along a z-axis of a three-dimensional orthogonal coordinate system (x, y, z) associated with the polarizer, at least two said layers having different refractive indices relative to one another,

each said layer having a shape, each said layer being a unit of lamination, the shape of each said layer being in a form of an undulated structure, said undulated structure consisting of a set of co-directed undulations, said undulated structure being a regularly or non-regularly undulated structure, at least one of said layers having a variable thickness,

the lamination along the z-axis repeating the shape and being configured to polarize light incident upon said multilayered structure.

2. The polarizer according to claim 1, wherein the polarizer has a first refractive medium layer containing at least one of Si and TiO₂ as a main component and a second refractive medium layer containing SiO₂ as a main component.

5. The polarizer according to claim 1, wherein the respective shape of at least one of said layers having a regularly undulated structure along the x-axis and being uniform along a y-axis.

6. The polarizer according to claim 1, wherein said first refractive medium layer has a first index of refraction, said second refractive medium layer has a second index of refraction, said first index of refraction being greater than said second index of refraction.

3. A method for producing a polarizer comprising the steps of:

laminating on a substrate a first refractive medium layer and a second refractive medium layer with a regularly repeating shape, at least one of said first medium layer and said second medium layer having a variable thickness, said laminating performed by a film-forming method at least partly including a step of sputter etching said first refractive medium layer and said second refractive medium layer, said substrate having at most one of each of a single set of regularly arranged, co-directed grooves, a single set of regularly arranged, co-directed projections, a single set of non-intersecting projections, and a single set of co-directed, non-intersecting grooves.

7. The method for producing a polarizer according to claim 3, wherein said substrate has at least one of said thin and long projections and said thin and long grooves.

4. A method of producing a polarizer, comprising the steps of:

laminating on a substrate a first refractive medium layer which contains at least one of Si and TiO₂ as a main component and a second refractive medium layer which contains SiO₂ as a main component with a regularly repeating shape, at least one of said first medium layer and said second medium layer having a variable thickness, said laminating performed by a film-forming method at least partly including a step of sputter etching said first refractive medium layer and said second refractive medium layer, said substrate having at most one of each of a single set of regularly arranged, co-directed grooves, a single set of regularly arranged, co-directed projections, a single set of non-intersecting projections, and a single set of co-directed non-intersecting grooves.