We investigate the correlation between the electrical and optical characteristics of selectively oxidized vertical-cavity surface-emitting lasers (VCSELs). Electrical derivative analysis is used on VCSELs to study the electrical performance and its correlation with the polarization-resolved optical powers and spectra. Characteristic features are shown in theIdV/dIcurves near major transition points of VCSEL operation. From theIdV/dIcurve we are able to precisely identify important operating currents such as the lasing threshold, the higher-order mode lasing current, and the cut-off current. Five operation regions are defined in the polarization-resolvedL−Icurves based on these currents and their temperature dependences are also studied. ©1997 American Institute of Physics.