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Updated: May 8, 2026
Fabrication of High Contrast Gratings for the Spectrum Splitting Dispersive Element in a Concentrated Photovoltaic System
Published on: July 18, 2015
Visible wavelength silicon nitride focusing grating coupler with AlCu/TiN reflector
Sebastian Romero-García1, Florian Merget, Frank Zhong
1Integrated Photonics Laboratory, RWTH Aachen University, Aachen, Germany. sromero@iph.rwth‑aachen.de
Abstract:
High-performance silicon nitride focusing grating couplers with AlCu/TiN reflectors for a visible wavelength (660 nm) have been designed and fabricated in a standard complementary metal-oxide-semiconductor pilot line. The influence of the bottom oxide cladding thickness on the grating decay length and efficiency is theoretically and experimentally investigated. It is shown how the metal reflector not only increases the efficiency but also allows reduction of the radiated beam size. Coupling efficiencies above 59% have been measured for compact focusing gratings.
