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Multi-directional radiation coupling in quantum-well infrared photodetectors

  • US 6,423,980 B1
  • Filed: 06/26/2000
  • Issued: 07/23/2002
  • Est. Priority Date: 06/25/1999
  • Status: Expired due to Fees
First Claim
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1. A device, comprising:

  • a detector layer having multiple quantum-well layers and responsive to radiation with a polarization component substantially parallel to said quantum-well layers; and

    a grating layer formed over said detector layer to have a two-dimensional array of grating unit cells and to diffract an input beam into at least one diffraction direction not perpendicular to said quantum-well layers, each unit cell shaped to define at least three different grating directions within said grating layer, wherein each unit cell includes a central region and a peripheral region conforming to and surrounding said central region, wherein central region and said peripheral region have different characteristics to effectuate a phase difference between a light ray reflected from said peripheral region and another light ray reflected from said central region.

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