This paper describes the properties of vertical-cavity semiconductor devices designed to emit light when driven in forward bias mode and detect optical radiation at wavelengths longer than that of emission when driven in reverse bias mode. The study of this type of devices is motivated by the miniaturization and integration into a single unit of the three functions that a microfluorimeter has to perform, optical pumping, optical detection, and optical filtering of weak light sources. The devices produced can generate fluorescence with a low output power since their emission wavelength can be tuned with that of maximum absorption of the fluorescent dye. We demonstrate also that they can detect low power fluorescence generated in a small volume of concentrated solution of a commercial dye. These devices can find useful application in microanalytical systems such as microfluidic devices or optical biochips. 2005 Society of Photo-Optical Instrumentation Engineers.