PROCEEDINGS ARTICLE | May 30, 2017
Proc. SPIE. 10249, Integrated Photonics: Materials, Devices, and Applications IV
KEYWORDS: GRIN lenses, Lithography, Electron beam lithography, Diffraction, Light emitting diodes, Sensors, Optical testing, Scanning electron microscopy, Photoresist materials, Telecommunications, Solids, 3D metrology, Measurement devices, Sensing systems, Photonic nanostructures, Goniophotometry
In this contribution, we present modification of far field of light emitting diode (LED) with implemented Fresnel structure in the LED surface. Fresnel structures were prepared in one-dimensional arrangement with two different foci f1 = 12.5 μm and f2 = 1 cm. Structures were etched directly in the LED emitting surface using electron beam lithography with the etched depth for the structure with f1 and f2 app. 200 nm and 400 nm, respectively. Due to application of these structures, LED far field narrowing was observed, which is documented by goniophotometer measurements. For the structure with f1 and f2, the intensity decrease for angles ±30° – ±50° is app. 3-4% and 5-6%, respectively, in comparison to the Lambertian profile.
