Inversion channel technology provides a straightforward way to integra
te lasers with detectors and transistors. One inversion channel laser
is the double heterostructure optoelectronic switch VCSEL which is rep
orted here with a 2.1mA threshold for a 10 mu m diameter device. A dep
osited stack of SiO2/TiO2 was used with post-growth etching of the cav
ity. Excellent electrical switching parameters of V-sw = 13V, V-h = 2.
1V and I-h = 0.5mA were obtained, making the device suitable for the d
igital optoelectronic sensing of small optical inputs.