Patent ID: 6903379
Filing Date: 2005-06-07
Classification: H01L

Abstract:
1. A light emitting diode comprising: (a) a stacked structure having a top surface, a bottom surface, edges extending between said top and bottom surfaces and an emitting junction extending generally in a horizontal plane above the bottom surface, said emitting junction having an emission wavelength; said stacked structure having vertical directions normal to the emitting junction, and (b) a reflective periodic diffraction grating disposed below said emitting junction on or in said stacked structure, said grating including a plurality of elements periodically spaced apart from one another in a repeat direction defining a set of first regions and second regions having different vertical elevations, such that said first regions project below said second regions by a predetermined distance, said first and second regions arranged to reflect light at phases differing by π, the periodic spacing of the first and second regions of said grating being operative to diffract light at said emission wavelength directed vertically downwardly from said emission layer so that a substantial portion of such light is reflectively diffracted in major diffraction directions oblique to the vertical and intersecting the edges of the structure.