Abstract: An ultrasonic imaging system for transmitting ultrasonic pulses into an object and detecting reflected ultrasonic waves therefrom. The system is provided with delay lines for real time imaging. The system comprises a probe means having a transmitting bundle of acoustic waveguides for transmitting ultrasonic pulses into an object. The transmitting bundle includes the delay lines which consists of having cladded acoustic waveguides of different lengths for introducing different delays in the ultrasonic pulses carried by each waveguide.

Abstract: An elastic waveguide, for propagating acoustic waves, consists of an elongated solid core region and an elongated solid outer cladding region. The acoustic waves propagate in a mode where the principle particle displacement is substantially parallel to the longitudinal axis of the waveguide, this mode is called longitudinal mode. The material densities and the bulk shear wave velocities of the core and cladding region are substantially the same but the bulk longitudinal wave velocity of the cladding region is larger than that of the core region.

Abstract: A birefringent single-mode acoustic fiber for propagating linearly polarized shear acoustic waves while preserving linear polarization, comprises an elongated core region of a solid material in which acoustic waves can be propagated in two orthogonal shear mode components, and a cladding region enclosing all surfaces of the core region except end surfaces thereof, the cladding region being also of a solid material in which acoustic waves can be propagated in two orthogonal shear mode components.