Material identification using spectroscopy and two laser light sources, e.g. for differentiation of human tissue - illuminating material with light at two wavelengths and determining intensity of luminescence or scattered light emitted from material in wavelength range below upper illuminating frequency

摘要

The method involves illuminating the material to be identified with a frequency lambda 1, detecting the intensity of light emitted from the material between wavelengths lambda 2 and lambda 3, and comparing with values for known materials. The material (11) to be identified is additionally illuminated with the light of a fourth wavelength (lambda 4). This lies above the wavelength range of the second and third wavelengths (lambda 2 and lambda 3). Two lasers (7,8) are used as light sources and respectively produce light of first and fourth wavelengths (lambda 1 and 4). The light is fed into an optical waveguide (10) across a beam splitter (9) and led to the material being identified. The light emitted is fed across a second beam splitter (12) to an evaluator (13). USE/ADVANTAGE - For removing layers of dirt, lacquer, etc. without harming substrate material; cutting using stencil; medical applications, e.g. stone and tumour destruction, plaque removal from teeth. Clearer differentiation between materials of similar types.