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

International audienceWe report on design, fabrication, and characterization of a vertical-cavity surface-emitting laser ͑VCSEL͒ 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. The increasing need for high-speed, efficient, compact, and low-cost devices for optoelectronic applications such as bidirectional optical interconnects, optical imaging, or telem-etry has recently led to focus on the optimization of dual-purpose vertical-cavity surface-emitting lasers ͑VCSELs͒ used as resonant cavity enhanced ͑RCE͒ photodetectors