Patent ID: 7012236

Claim:
A device comprising a sensor, said sensor comprising two or more mutually separated sensor elements that deliver an output signal with a strength which is dependent on the intensity applied one of the two or more sensor elements, wherein: a greatest dimension of a sensor element is at most equal to half the diameter of a diffraction-limited spot of a beam exiting an optic fiber at the location of the sensor elements, a diametrical dimension of the portion of the sensor provided with sensor elements is greater than the diameter of the beam exiting from the optical fiber, and a means for determining the strength of the output signal from each sensor element, and wherein the device further comprises a supply for supplying output signals delivered by the sensor elements to a processing device, and an adjustment means for adjusting the supply so as to supply or not supply output signals from the sensor elements to the processing device in dependence on the strength of the output signal from the sensor element, which adjustment means comprise said means for determining the strength of the output signal from each sensor element.