A system and method that replaces safety requirements of a laser detection system by shifting the wavelength of a detection laser. An optical wavelength converter that shifts the optical wavelength of a detection laser from a first wavelength within the Infrared “A” portion of the spectrum to a more eye-safe wavelength. The detection laser is directed to the surface of a remote target. Ultrasonic displacements at the surface scatter the filtered detection laser. Collection optics then gather phase modulated light scattered by the surface and direct the phase modulated light to an optical processor that produces a signal representative of the ultrasonic displacements. Signal processors then determine the internal structure of the remote target based on the signal.