Abstract
This study is an attempt to investigate the effect of grading layers thicknesses and doping on the distributed Bragg reflectors (DBRs) resistivity by using advanced numerical simulation (ISETCAD) . Various VCSEL with and without grading DBRs aredesigned. It was observed increasing the length of grading minimize the voltage drop on the device, especially for p DBR. And total resistance of the device can be further lowered if all grading layers are all highly doped.