Title :
Effect of GaAs/AlGaAs quantum-well structure on refractive index
Author :
Lin, Chih-Hsiang ; Meese, J.M. ; Wroge, M.L. ; Weng, Chun-Jen
Author_Institution :
Dept. of Electr. & Comput. Eng., Missouri Univ., Columbia, MO, USA
fDate :
5/1/1994 12:00:00 AM
Abstract :
We investigate the refractive index difference between the GaAs/AlGaAs quantum wells (QWs) and bulk AlGaAs. We find the refractive index difference is smaller when the electric field in the nominally intrinsic MQW region is larger, or when the well (GaAs) thickness of the QW´s is larger, or when the Al fraction of the QWs is smaller. The maximum refractive index difference between the 100 /spl Aring/ GaAs/100 /spl Aring/ Al/sub 0.2/Ga/sub 0.8/As QWs at zero electric filed and bulk Al/sub 0.1/Ga/sub 0.9/As is about 0.044. Even with a small refractive index difference of 0.0132, the OFF-state reflectance of a normally-off MQW modulator at the designed photon wavelength will increase from the desired value of 0% to 90% when the reflectivity of the bottom mirror is 0.99.<>
Keywords :
III-V semiconductors; aluminium compounds; electro-optical devices; electroreflectance; gallium arsenide; optical modulation; refractive index; semiconductor quantum wells; Al/sub 0.1/Ga/sub 0.9/As; GaAs-Al/sub 0.2/Ga/sub 0.8/As; GaAs/AlGaAs quantum-well; MQW modulator; bulk AlGaAs; electric field; reflectance; refractive index; Gallium arsenide; Mirrors; Optical modulation; Optical reflection; Optical refraction; Optical variables control; Quantum well devices; Quantum wells; Reflectivity; Refractive index;
Journal_Title :
Photonics Technology Letters, IEEE
