LOW-RESISTANCE INTRACAVITY-CONTACTED OXIDE-APERTURE VCSELS

The authors study, analytically and experimentally, the extrinsic seri es resistance in intracavity-contacted vertical-cavity surface-emittin g lasers (VCSEL's). Low resistance, low threshold-current, intracavity -contacted VCSEL's are fabricated, with resistances ranging from 355 O hm for 4-mu m square apertures to 80 Ohm for 12-mu m square apertures and threshold voltages as low as 1.35 V, To the best of our knowledge, these are the lowest values reported for this type of VCSEL, The thre shold currents range from 270 mu A for 4 mu m x 4 mu m apertures to 85 0 mu A for 12 x 12 mu m From a comparison of the resistance as a funct ion of oxide aperture radius, the measured data follows closely with t he calculated data, demonstrating the validity of the derived expressi ons for series resistance.