Acousto-optic vibrometer

An acousto-optic vibrometer comprising:

• an acoustic wave source;
• an acoustic lens system which places a scattered wave, created by irradiating an object with an acoustic wave that has been emitted from the acoustic wave source, into the scattered wave having a predetermined converged state;
• an acousto-optic medium portion which is arranged so that the scattered wave that has been transmitted through the acoustic lens system is incident on the acousto-optic medium portion;
• a sensing light source to emit a sensing light beam in which a plurality of monochromatic rays of light with mutually different traveling directions are superposed one upon the other and which is incident on the acousto-optic medium portion at an angle with respect to, and neither perpendicularly nor parallel to, the acoustic axis of the acoustic lens system;
• a reference light source to emit a reference light beam which includes a plurality of monochromatic rays of light traveling into mutually different directions are superposed one upon the other and which is to be superposed on diffracted light that has been produced with the sensing light beam at the acousto-optic medium portion;
• an imaging lens system which converges the diffracted light on which the reference light beam is superposed;
• and
• an image receiving section which senses the light that has been converged by the imaging lens system to output an electrical signal.