skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: GaAs micro-pyramids serving as optical micro-cavities

Abstract

An efficient light-matter coupling requires high-quality (Q) micro-cavities with small mode volume. We suggest GaAs micro-pyramids placed on top of AlAs/GaAs distributed Bragg reflectors to be promising candidates. The pyramids were fabricated by molecular-beam epitaxy, electron-beam lithography and a subsequent wet-chemical etching process using a sacrificial AlAs layer. Measured Q-factors of optical modes in single pyramids reach values up to 650. A finite-difference time-domain simulation assuming a simplified cone-shaped geometry suggests possible Q-factors up to 3600. To enhance the light confinement in the micro-pyramids we intend to overgrow the pyramidal facets with a Bragg mirror--results of preliminary tests are given.

Authors:
; ; ; ; ; ;  [1]
  1. Institut fuer Angewandte Physik and Center for Functional Nanostructures (CFN), Universitaet Karlsruhe (Thailand), Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe (Germany)
Publication Date:
OSTI Identifier:
21371409
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1199; Journal Issue: 1; Conference: 29. international conference on the physics of semiconductors, Rio de Janeiro (Brazil), 27 Jul - 1 Aug 2008; Other Information: DOI: 10.1063/1.3295456; (c) 2009 American Institute of Physics
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM ARSENIDES; COMPUTERIZED SIMULATION; COUPLING; FINITE DIFFERENCE METHOD; GALLIUM ARSENIDES; INTERFACES; LAYERS; MIRRORS; MOLECULAR BEAM EPITAXY; OPTICAL MODES; PHOTOLUMINESCENCE; SEMICONDUCTOR MATERIALS; VISIBLE RADIATION; ALUMINIUM COMPOUNDS; ARSENIC COMPOUNDS; ARSENIDES; CALCULATION METHODS; CRYSTAL GROWTH METHODS; ELECTROMAGNETIC RADIATION; EMISSION; EPITAXY; GALLIUM COMPOUNDS; ITERATIVE METHODS; LUMINESCENCE; MATERIALS; MATHEMATICAL SOLUTIONS; NUMERICAL SOLUTION; OSCILLATION MODES; PHOTON EMISSION; PNICTIDES; RADIATIONS; SIMULATION

Citation Formats

Karl, M., Beck, T., Li, S., Hu, D. Z., Schaadt, D. M., Kalt, H., and Hetterich, M. GaAs micro-pyramids serving as optical micro-cavities. United States: N. p., 2010. Web. doi:10.1063/1.3295456.
Karl, M., Beck, T., Li, S., Hu, D. Z., Schaadt, D. M., Kalt, H., & Hetterich, M. GaAs micro-pyramids serving as optical micro-cavities. United States. doi:10.1063/1.3295456.
Karl, M., Beck, T., Li, S., Hu, D. Z., Schaadt, D. M., Kalt, H., and Hetterich, M. 2010. "GaAs micro-pyramids serving as optical micro-cavities". United States. doi:10.1063/1.3295456.
@article{osti_21371409,
title = {GaAs micro-pyramids serving as optical micro-cavities},
author = {Karl, M. and Beck, T. and Li, S. and Hu, D. Z. and Schaadt, D. M. and Kalt, H. and Hetterich, M.},
abstractNote = {An efficient light-matter coupling requires high-quality (Q) micro-cavities with small mode volume. We suggest GaAs micro-pyramids placed on top of AlAs/GaAs distributed Bragg reflectors to be promising candidates. The pyramids were fabricated by molecular-beam epitaxy, electron-beam lithography and a subsequent wet-chemical etching process using a sacrificial AlAs layer. Measured Q-factors of optical modes in single pyramids reach values up to 650. A finite-difference time-domain simulation assuming a simplified cone-shaped geometry suggests possible Q-factors up to 3600. To enhance the light confinement in the micro-pyramids we intend to overgrow the pyramidal facets with a Bragg mirror--results of preliminary tests are given.},
doi = {10.1063/1.3295456},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1199,
place = {United States},
year = 2010,
month = 1
}
  • We propose phase shift multiplication effect of all-optical analog to electromagnetically induced transparency in two photonic crystal micro-cavities side coupled to a waveguide system through external optical pump beams. With dynamically tuning the propagation phase of the line waveguide, the phase shift of the transmission spectrum in two micro-cavities side coupled to a waveguide system is doubled along with the phase shift of the line waveguide. π-phase shift and 2π-phase shift of the transmission spectrum are obtained when the propagation phase of the line waveguide is tuned to 0.5π-phase shift and π-phase shift, respectively. All observed schemes are analyzed rigorouslymore » through finite-difference time-domain simulations and the coupled-mode formalism. These results show a new direction to the miniaturization and the low power consumption of microstructure integration photonic devices in optical communication and quantum information processing.« less
  • Picosecond time-resolved photoluminescence (PL) spectroscopy has been used to investigate the optical properties of GaN pyramids overgrown on hexagonal-patterned GaN(0001) epilayers on sapphire and silicon substrates with AlN buffer layers. We found that: (i) the release of the biaxial compressive strain in GaN pyramids on GaN/AlN/sapphire substrate led to a 7 meV redshift of the spectral peak position with respect to the strained GaN epilayer grown under identical conditions; (ii) in the GaN pyramids on GaN/AlN/sapphire substrate, strong band edge transitions with much narrower linewidths than those in the GaN epilayer have been observed, indicating the improved crystalline quality ofmore » the overgrown pyramids; (iii) PL spectra taken from different parts of the pyramids revealed that the top of the pyramid had the highest crystalline quality; and (iv) the presence of strong band-to-impurity transitions in the pyramids were primarily due to the incorporation of the oxygen and silicon impurities from the SiO{sub 2} mask. {copyright} {ital 1999 American Institute of Physics.}« less
  • Transformation of self-assembled crystalline TiO{sub 2} nanorods to amorphous layer, and the corresponding impact on optical-bandgap (E{sub g}) on Si pyramids are investigated by irradiating with 50 keV Ar{sup +}-ions. Initially, E{sub g} is found to be reduced from 3.23 to 2.94 eV up to a fluence of 1 × 10{sup 16} ions/cm{sup 2}, and discussed in terms of the rise in oxygen vacancies (V{sub O}). However, a sudden increase in E{sub g} to 3.38 eV is detected at a fluence of 1 × 10{sup 17} ions/cm{sup 2} through evolution of voids by over-saturating V{sub O}, manifesting the appearance of degenerate states by shifting the Fermi levelmore » above the conduction band minimum via Burstein-Moss effect.« less