@InProceedings{Supelec524,
author = {Claire Alhenc-Gelas and Paul Heroin and Mohamed Abid and Joel Jacquet and Simon Gautier and Abdallah Ougazzaden},
title = {{Design rules of high reflectivity Bragg GaAlN mirrors for 300nm VCSELs}},
year = {2009},
booktitle = {{Proceedings of SPIE : Vertical-Cavity Surface-Emitting Lasers XIII}},
volume = {7229},
number = {0N},
pages = {1-12},
month = {Feb},
address = {San Jose, CA (USA)},
url = {http://dx.doi.org//10.1117/12.808743},
doi = {10.1117/12.808743},
abstract = {Vertical Cavity Surface Emitting Lasers (VCSELs) emitting in the
Ultra Violet (UV) wavelength range (300 nm) are of great
importance for spectroscopy, storage, or medical applications.
GaAlN based material is well appropriate to achieve this
objective. We have developed a model that takes into account
band-gap, absorption, refractive index of GaAlN material as
function of its composition and used it to define the rules for
the design of high reflectivity GaAlN based Bragg reflectors. On
one hand, the index contrast between the two materials of the
Bragg mirror has to be as high as possible to have a limited
number of periods and high reflectivity. On the other hand, we
are limited by two phenomena to reach the lowest lasing
wavelength : the absorption of the material and the lattice
mismatch between the two material used in the mirror. In other
words, starting with AlN/GaN couple of material that offers the
highest index contrast, we have to increase the Ga content in
AlN layer to have a better lattice matching with GaN and to
increase the content of Al in GaN layer to limit the absorption
of the material. This paper will discuss the trade - off that
has to be considered to get high reflectivity mirror with the
lowest number of period for very short wavelength (300nm).}
}