Circular polarizer using frequency selective surfaces

• US 20060227422A1
• Filed: 04/12/2005
• Published: 10/12/2006
• Est. Priority Date: 04/12/2005
• Status: Abandoned Application

• Current Assignee: Brian Monacelli, Glenn Boreman
• Original Assignee: Brian Monacelli, Glenn Boreman
• Inventors: Monacelli, Brian, Boreman, Glenn
• Application Number:
  US11/104,138
• Publication Number:
  US 20060227422A1
• Time in Patent Office: Days
• US Class Current: 359/485
• CPC Class Codes: G02B 27/286 for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34

Abstract

A circular polarizer (CP) includes an electrically insulating or semiconducting and optically transparent layer having a frequency selective surface (FSS) disposed thereon, the FSS includes a periodic array of electrically conductive spirals. For reflection mode operation, an electrically conducting substrate or ground plane layer preferably having a thickness of approximately one-quarter wave at the nominal design wavelength is disposed beneath the optically transparent layer.

Claims

1. A circular polarizer (CP), comprising:

an optically transparent and electrically insulating or semiconducting layer, and

a frequency selective surface (FSS) disposed on said optically transparent layer, said FSS comprising a periodic array of spaced apart electrically conductive spiral shaped features.

3. The circular polarizer of claim 1, further comprising a ground plane disposed beneath said optically transparent layer, wherein said circular polarizer is a reflection-mode circular polarizer.

4. The circular polarizer of claim 3, wherein said optically transparent layer has a thickness of approximately one-quarter wave at a nominal design wavelength for said CP.

5. The circular polarizer of claim 1, wherein said optically transparent layer comprises amorphous silicon.

6. The circular polarizer of claim 1, further comprising a support layer beneath said optically transparent layer.

7. The circular polarizer of claim 6, wherein said support layer comprises a semiconductor die.

8. The circular polarizer of claim 6, wherein said support layer comprises a flexible material.

9. The circular polarizer of claim 1, wherein said spaced apart electrically conductive spiral shaped features are nanoscale features.

10. The circular polarizer of claim 1, wherein said spaced apart electrically conductive spiral shaped features comprise at least one transition metal selected from the group consisting of Mn, Ni, Cr, Cu and V.

11. The circular polarizer of claim 10, wherein said transition metal is Mn.

12. The circular polarizer of claim 9, wherein said circular polarizer processes infrared signals in range between 3 and 15 μ

m.

13. The circular polarizer of claim 1, further comprising a superstrate layer disposed on said FSS.

2. The circular polarizer of claim 17 wherein said FSS is the only optically reflective component included with said CP, wherein said circular polarizer is a transmission-mode CP.