Multiple-wavelength vertical-cavity surface-emitting laser (MW-VCSEL)
arrays are fabricated using two patterned-substrate growth techniques
both in conjunction with a location-resolvable in situ laser reflectom
eter in a molecular beam epitaxy (MBE) system, a backside pattern on t
he substrate is used to induce a temperature profile on the growth sur
face, Ena the first technique, we used a temperature-dependent growth
rate to create MW-VCSEL's, whereas for the second, uniform growth was
first performed followed by a temperature-dependent re-desorption proc
ess to create the thickness gradient required for MW-VCSEL's. We achie
ved a record wavelength span, accurate and repeatable lasing wavelengt
hs, and reproducible multiple-wavelength VCSEL arrays with high perfor
mance. Comparison between the two methods will be discussed.