Experimental demonstration of oxide-mode influence in a dual-purpose oxide-confined vertical-cavity surface-emitting laser/resonant detector

We report on design, fabrication, and characterization of a vertical-cavity surface-emitting laser (VCSEL) used as a resonant-cavity-enhanced detector for dual-purpose application. The geometry of this oxide-confined VCSEL takes advantage of the properties of the buried oxide layer to allow both single-mode laser emission and detection on a large surface. Here, we demonstrate the presence and the influence of oxide modes in the optical sensitivity spectrum of the device through spatially localized detection measurements. The wavelength of these modes has been correlated to the dip on the reflectivity spectrum measured at the same area of the device surface.