Patent ID: 8280494

Claim:
A measurement apparatus configured to measure a spectroscopic characteristic in an object, said measurement apparatus comprising: a first measurement unit configured to irradiate the object with at least three types of ultrasonic waves and light, the at least three types of ultrasonic waves including a first ultrasonic wave having a first frequency and a first amplitude, a second ultrasonic wave whose frequency equals the first frequency and having a second amplitude different from the first amplitude, and a third ultrasonic wave having a second frequency different from the first frequency and having an amplitude that equals the first amplitude, and to measure non-modulated light and modulated light that has been modulated by an acousto-optical effect caused by an interaction between the light and the ultrasonic waves irradiated onto the object; and a signal processor configured to calculate: a first modulation depth, which is a ratio between an intensity of non-modulated light and an intensity of the modulated light when the first ultrasound wave is irradiated, a second modulation depth, which is a ratio between the intensity of non-modulated light and an intensity of the modulated light when the second ultrasonic wave is irradiated, and a third modulation depth, which is a ratio between the intensity of the non-modulated light and an intensity of the modulated light when the third ultrasonic wave is irradiated, and to calculate a scattering characteristic and an absorption characteristic in the object on the basis of: a change rate of a modulation depth to a change of the amplitude of the ultrasonic wave based on a change between the first modulation depth and the second modulation depth and a change between the first amplitude and the second amplitude; and a change rate of a modulation depth to a change of the frequency of the ultrasonic wave based on the change between the first modulation depth and the third modulation depth and a change between the first frequency and the second frequency.