TY - JOUR
T1 - Microreflectivity studies of wavelength control in oxidised AlGaAs microcavities
AU - Macaluso, R.
AU - Robert, F.
AU - Bryce, A.C.
AU - Calvez, S.
AU - Dawson, M.D.
PY - 2003/2/8
Y1 - 2003/2/8
N2 - Wet oxidation of GaAs/AlGaAs structures is an important technique in the processing of advanced devices such as vertical cavity surface emitting lasers (VCSELs). In one VCSEL application, the low-index and electrically-insulating AlxOy layers have been used to obtain high-reflectivity and broad bandwidth distributed Bragg reflector mirrors (DBRs). A further recent development has shown that combined lateral-vertical oxidation of intracavity AlGaAs layers can be used to tune the resonant wavelength of a semiconductor microcavity. The slow oxidation rate limits the lateral scale of practical wet oxidation to mesas structures of 50-100 m in width. Therefore post-processing assessment of spectral changes requires microreflectivity measurement capability with high spatial resolution. In the following, we describe the fabrication and assessment of microcavity structures in the 1.3 m range. The micro-reflectivity set-up consists of microscope-objective focussing of broadband light, combined with optics to relay the data to a spectrograph, and a CCD camera for alignment. This simple set-up allows the measurement of calibrated reflectivity for features down to a few 10's of m in size over a large spectral range (600-1800 nm). We present microreflectivity measurements of wide-bandwidth oxidised DBRs, and most significantly, for the first time to our knowledge, of oxidation control of the resonant wavelength of a microcavity in the 1.3 m range.
AB - Wet oxidation of GaAs/AlGaAs structures is an important technique in the processing of advanced devices such as vertical cavity surface emitting lasers (VCSELs). In one VCSEL application, the low-index and electrically-insulating AlxOy layers have been used to obtain high-reflectivity and broad bandwidth distributed Bragg reflector mirrors (DBRs). A further recent development has shown that combined lateral-vertical oxidation of intracavity AlGaAs layers can be used to tune the resonant wavelength of a semiconductor microcavity. The slow oxidation rate limits the lateral scale of practical wet oxidation to mesas structures of 50-100 m in width. Therefore post-processing assessment of spectral changes requires microreflectivity measurement capability with high spatial resolution. In the following, we describe the fabrication and assessment of microcavity structures in the 1.3 m range. The micro-reflectivity set-up consists of microscope-objective focussing of broadband light, combined with optics to relay the data to a spectrograph, and a CCD camera for alignment. This simple set-up allows the measurement of calibrated reflectivity for features down to a few 10's of m in size over a large spectral range (600-1800 nm). We present microreflectivity measurements of wide-bandwidth oxidised DBRs, and most significantly, for the first time to our knowledge, of oxidation control of the resonant wavelength of a microcavity in the 1.3 m range.
KW - microreflectivity
KW - optical cavity
KW - wavelength-control
KW - wet oxidation
UR - http://dx.doi.org/10.1016/S0921-5107(02)00645-1
U2 - 10.1016/S0921-5107(02)00645-1
DO - 10.1016/S0921-5107(02)00645-1
M3 - Article
VL - 102
SP - 317
EP - 322
JO - Materials Science and Engineering B
JF - Materials Science and Engineering B
SN - 0921-5107
IS - 1
ER -