Semiconductor emitter/detector optical device formed as resonant cavity light emitting device, typically for analysis of biological samples

摘要

A semiconductor optical device being a resonant cavity device in this form of an LED comprises a single substrate arranged for emitting light (O) for incidence on a sample or other element and also responsive to light (D), e.g. of a different wavelength, received back from this sample or other element: the device further comprises means for monitoring a characteristic (e.g. its current-voltage characteristic) which varies in dependence upon the light (D) received back from the sample or other element.