High sensitivity photodetector device with integrated micrometric diaphragm for confocal microscopes

Photodetector device comprising a semiconductor substrate of a first type of conductivity connected to a first electrode. Said substrate comprises an active area made up of different semiconductor regions of a second type of conductivity insulated from each other and connected to respective second electrodes so that each of them can be connected separately from the others to an appropriate bias voltage. By regulating the bias voltages applied to these regions the function of optic diaphragm of the device can be controlled. The device works without needing any form of optical insulation between the different regions of the active area and always uses the same single output electrode for the signal in all the different situations of diaphragm adjustment.