Patent ID: 7123844

Claim:
A method of adjusting the intensity of light in an optical spectroscopy system from a light source that emits light having an expected average wavelength spectrum to maintain the reliability of a light signal from said light source, said method comprising the steps of: modulating a first said light signal by an optical filter configured to weight the intensity of said first light signal by wavelength according to a regression vector that identifies a difference between said average spectrum and a wavelength spectrum of said first light signal from said light source; comparing the intensity of said modulated first light signal to an intensity expected if said wavelength spectrum of said first light signal equaled said average spectrum; and adjusting a power input to said light source responsively to said comparing step to a degree so that a subsequent said light signal defines a wavelength spectrum that is closer to said average spectrum, as measured by said modulating and comparing steps, than said wavelength spectrum of said first light signal.