The present invention for detecting ultasonic displacements includes a detection laser to generate a first pulsed laser beam to generate the ultrasonic surface displacements on a surface of the target. A seocond pulsed laser beam to detect the ultrasonic surface displacements on a surface of the target. Collection optics to collect phase modulated light from the first pulsed laser beam either reflected or scattered by the target. An interferometer which processes the phase modulated light and generate at least one output signal. A processor that processes the at least one output signal to obtain data representative of the ultrasonic surface displacements at the target.