| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method of separating light signal into spectral components using an acousto-optical tunable filter, in particular, a method for measuring a substance concentration, by emitting laser beams into the atmosphere to measure rear side scattered beams, using the acousto-optical tunable filter in a method of measuring remotewisely an aiming substance such as an atom, a molecule and a toxic substance in the atmosphere using the laser beams. SOLUTION: In this spectrometry, the laser beam having a wavelength absorbed by a specified substance and a laser beam, having a wavelength which is not absorbed by the specified substance, are emitted into the atmosphere, the rear side scattered beams returned by its backward scattering with steam, aerosol or the like after the emitted laser beams are absorbed by the substance are passed through a spectroscopic filter to measure respective transmitted beam intensities, and the concentrations of the atoms, molecules, toxic substances or the like in the atmosphere are measured, based on an intensity ratio provided therein. The acousto-optical tunable filter is used as the spectroscopic filter, and a frequency thereof is changed to control the wavelength of the transmitted beam, so as to enable spectroscopic measurement over a wide range of wavelengths.</p> |
