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Updated: May 18, 2026
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Fabrication of High Contrast Gratings for the Spectrum Splitting Dispersive Element in a Concentrated Photovoltaic System
Published on: July 18, 2015
Sub-wavelength GaN-based membrane high contrast grating reflectors
Tzeng Tsong Wu1, Yu Cheng Syu, Shu Hsien Wu
1Department of Photonics & Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu 30050, Taiwan.
Optics Express
|October 6, 2012
Summary
Researchers fabricated Gallium Nitride (GaN)-based membrane high contrast gratings (HCGs) for enhanced light reflection. Optimized designs achieved high reflectivity and broad bandwidth, aiding novel GaN light-emitting device development.
Area of Science:
- Materials Science
- Optoelectronics
- Nanotechnology
Background:
- High contrast gratings (HCGs) are crucial optical components.
- Gallium Nitride (GaN) is a key material for optoelectronic devices.
Purpose of the Study:
- To design and fabricate efficient GaN-based membrane HCG reflectors.
- To achieve high reflectivity with a broad bandwidth for optical applications.
Main Methods:
- Rigorous Coupled-Wave Analysis (RCWA) and Finite-Difference Time-Domain (FDTD) methods for optical simulation.
- E-beam lithography and focused-ion beam (FIB) processes for fabrication.
- Micro-reflectivity spectroscopy for experimental characterization.
Main Results:
- Optimized structural parameters for GaN-based membrane HCGs were determined.
- Fabricated HCGs demonstrated high reflectivity at 460 nm.
- A large stopband width of 60 nm was achieved for TE polarization.
- Experimental results closely matched simulation predictions.
Conclusions:
- Successful fabrication of GaN-based membrane HCG reflectors with excellent optical performance.
- The study provides a foundation for developing advanced GaN-based light-emitting devices.
- Potential applications in blue and UV optoelectronics.
