A biological observation apparatus and method for obtaining information indicative of internal state of and object using sound wave and light are provided to obtain the information in the deep portion of the subject in the high S/N at high speed. The biological observation apparatus(1) is prepared. The sound wave radiation unit radiates the sound wave having the predetermined wavelength or the frequency to the subject. The control unit controls the radiation state of the sound wave radiated in the subject. The light radiation unit(2) radiates the light within the subject while gradually diversifying the wavelength of the light. The light reception unit receives the object light when the radiated light from the light radiation unit in the inside of the subject is reflected. The first object light is received with the light receiving unit. The second subject light acquires the first coherent light generated by the interference between the radiated light and is received by the light reception unit. The optical detecting part(27) acquires the second coherent light generated by the interference between the light coming out. The operation unit(7) calculates the information of the deep portion of the subject in which the sound wave radiates.
BIOLOGICAL OBSERVATION APPARATUS AND METHOD FOR OBTAINING INFORMATION INDICATIVE OF INTERNAL STATE OF AN OBJECT USING SOUND WAVE AND LIGHT