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Published on: July 18, 2015
Polarization-dependent GaN surface grating reflector for short wavelength applications.
Joonhee Lee1, Sungmo Ahn, Hojun Chang
1Department of Physics and Astronomy & Inter-university Semiconductor Research Center, Seoul National University, Seoul 151-747, Korea.
Optics Express
|January 7, 2010
Summary
Researchers developed a simple GaN surface grating reflector (SGR) for blue light. This novel photonic device achieves over 90% reflectance, simplifying GaN-based short-wavelength device fabrication.
Area of Science:
- Photonics
- Materials Science
- Optoelectronics
Background:
- Gallium Nitride (GaN) based devices are crucial for short-wavelength optoelectronics.
- Efficient high reflectors are essential components in photonic integrated circuits.
- Existing GaN reflector technologies face challenges in fabrication simplicity and integration.
Purpose of the Study:
- To propose and demonstrate a novel one-dimensional sub-wavelength grating structure on GaN.
- To design a Gallium Nitride surface grating reflector (SGR) for transverse-electric polarized light in the blue wavelength range.
- To investigate the fabrication feasibility and performance of the proposed SGR.
Main Methods:
- Utilized rigorous coupled-wave analysis (RCWA) to simulate and optimize grating structural parameters.
- Employed holographic lithography for precise grating pattern definition.
- Applied dry etching techniques for the fabrication of the GaN surface grating reflector.
- Measured reflectance spectra to validate simulation results.
Main Results:
- The designed GaN SGR demonstrated high reflectance exceeding 90% across a 60-nm bandwidth.
- Experimental results closely matched the predictions from rigorous coupled-wave analysis simulations.
- The fabricated SGR exhibited excellent performance for transverse-electric polarized light.
Conclusions:
- The developed one-dimensional sub-wavelength grating structure effectively functions as a high reflector on GaN.
- The structural simplicity of the GaN SGR facilitates fabrication and integration into photonic devices.
- This technology offers a promising solution for enhancing GaN-based short-wavelength photonic applications.
