Patent ID: 7139071

Claim:
A spectroscopy method, comprising: illuminating or irradiating a sample to obtain a spectrum of scattered light; analysing the spectrum; passing a plurality of components of the analysed spectrum to a photodetector, wherein light scattered from a given plane in the sample is brought to a tight focus in a given area on the photodetector and light scattered from other planes in the sample is brought to a more diffuse focus on the photodetector; wherein light received in said given area is detected without or separately from light outside the given area, thereby reducing the effect of light scattered from other planes in the sample; characterised in that the position of the given area on the photodetector in which light received is detected may be moved in order that light from a first point in a given plane of the sample is detected by the given area in a first position on the photodetector and light from a second point in the given plane of the sample is detected by the given area in a second position on the photodetector.