Laser excitation of longitudinal and shear ultrasound waves pulses in solid state bodies in a near zone

The pecularities of the optical-acoustical excitation of the acoustical pulse of longitudinal and shear ultrasonic waves for the near Fresnel zone and acoustical diffraction on the rectangular opening are investigated. Some enhancement of the acoustical pulse amplitude and reduction of the duration under transition from the nearest Fresnel zone to the far Fraunhofer zone are stated. It has been shown that under displacement from the center of the opening in the Fresnel zone the amplitude of acoustical pulse is reduced and duration is enhanced. The pulse amplitude is reduced significantly under transition to the geometrical shadow.