Laser ultrasonics-based material analysis system and method

A system for determining a characteristic of a target, comprising:

• impulse means for generating an impulse beam and for directing said impulse beam over a target path distance to a surface of the target for launching an elastic wave within the target;
• interferometer means for detecting a displacement of the surface of the target in response to the launched elastic wave, said interferometer means including a semiconductor laser diode generating an output beam;
• means for generating a target probe beam and a reference beam from said output beam;
• means for determining a time varying characteristic of said elastic wave within the target from said detected displacement;
• means for correlating said determined time varying characteristic with a property of interest of the target;
• and
• means for substantially equalizing a path length of said target probe beam to a path length of said reference beam to compensate for frequency jitter in said output beam.