Optical measuring device with wavelength-selective light source

摘要

A light equipment(202) irradiating a target(200) with light adjusts light from a light source(6) in a light source optical system(216) and introduces the same into an acousto-optic device(4), for separating the same into its spectral components and modulating the same in the acousto-optic device(4). A condensing optical system(20) condenses primary light outgoing from the acousto-optic device(4), so that an irradiation optical system(220) irradiates a target(200) with the same. A photodetector(204) comprises a photoreceiving part(230) and a data processing part(107), so that the photoreceiving part(230) converts a signal responsive to the fluctuation of modulated measuring light to a plurality of signals of different degrees of amplification simultaneously outputting same. The data processing part(107) selects a non-saturated value of an amplifier or an A-D convertor while maintaining the largest degree of amplification from these signals, and lock-in processes same with a modulation frequency modulating the measuring light. A specific substance in a scattering substance can be non-invasively measured with high accuracy. <IMAGE>