Measuring apparatus and measuring method for metallic microstructures or material properties

A measuring apparatus for metallic microstructures or material properties, comprising:

• a pulse laser oscillator configured to output a first laser beam;
• a beam splitter configured to split the output first laser beam into split beams;
• optical paths configured to propagate light of split beams split by the beam splitter, respectively, taking different times for light propagation thereof;
• a condenser configured to superimpose light of split beams propagated through the optical paths, respectively, on an identical spot of a measuring material, for irradiation therewith;
• a laser interferometer configured to irradiate the measuring material with light of a second laser beam, and have light intensity variations resulted from interferences between reference light and light of the second laser beam reflected or scattered from the measuring material, as bases to detect ultrasonic waves energized by light of the first laser beam and transmitted in the measuring material;
• and
• a waveform analyzer configured to calculate a metallic microstructure or a material property of the measuring material based on ultrasonic waves detected by the laser interferometer.