Fig. 1 The signal generator produces the desired waveform which is then amplified by the RF amplifier and delivered to the transducer. The scanning system moves the transducer in the xy -plane, and at several distances (depending on transducer focal distances), from the scanning plane to build up... More about this image found in The signal generator produces the desired waveform which is then amplified ...

Fig. 2 ( a ) Schematic diagram representing the vertical cross-sectional view of the spherical transducer system and ( b ) 2D axisymmetric model in comsol More about this image found in ( a ) Schematic diagram representing the vertical cross-sectional view of t...

Fig. 3 Simulated and experimental PSFs of the transducers with different frequencies: ( a ) 10 MHz, ( b ) 15 MHz, ( c ) 20 MHz, ( d ) 30 MHz, and ( e ) 40 MHz. The upper row represents the simulated PSF, and the lower row represents the experimental PSF, respectively. More about this image found in Simulated and experimental PSFs of the transducers with different frequenci...

Fig. 4 ( a ) Simulated beam formation by the spherical transducer showing the point focus at the optical axis, ( b and c ) Line profiles of the axial (denoted as Z axis) and transverse (denoted as r axis) pressure distributions, ( d ) 3D view of PSF of the focused 50 MHz ultrasonic transduce... More about this image found in ( a ) Simulated beam formation by the spherical transducer showing the poin...

Fig. 5 ( a ) Positive axicon lens diverging ultrasonic waves in acoustics, with a perspective view showing the conical shape and divergence pattern, and a cross-sectional view illustrating the wave propagation, ( b ) Negative axicon lens focusing ultrasonic waves in acoustics, with a perspective v... More about this image found in ( a ) Positive axicon lens diverging ultrasonic waves in acoustics, with a ...

Fig. 6 ( a – c ) Two-dimensional field distribution curve of the axicon lenses for apex angles 120 deg, 140 deg, and 160 deg, respectively. ( d – i ) Corresponding line profiles along the axial (representing DOF) and transverse (representing transverse resolution) directions of the 2D field distri... More about this image found in ( a – c ) Two-dimensional field distribution curve of the axicon lenses for...

Fig. 7 Perspective views and corresponding cross-sectional views of different lenses: ( a ) Spherical lens, showing its curvature and focal properties, ( b ) Single axicon lens, highlighting its conical shape and the resulting line focus, and ( c ) Central flat axicon lens, illustrating the flat c... More about this image found in Perspective views and corresponding cross-sectional views of different lens...

Fig. 8 ( a ) Beam formation by a conventional axicon lens, showing the DOF confined to a region very close to the transducer, ( b ) Beam formation by the proposed central flat axicon lens, illustrating a customizable depth of focus region, and ( c ) Ray diagram of the central flat axicon lens, dep... More about this image found in ( a ) Beam formation by a conventional axicon lens, showing the DOF confine...

Fig. 9 ( a ) Simulated beam formation by the central flat axicon lens showing the line focus along the optical axis, ( b ) Axial pressure distribution showing flat pressure variation in the DOF region compared to conventional single axicon, ( c ) Transverse beam profile of the modified lens, and (... More about this image found in ( a ) Simulated beam formation by the central flat axicon lens showing the ...

Fig. 10 ( a ) Perspective 3D view of the double axicon lens, showing the arrangement and orientation of the double axicon lenses, ( b ) Cross-sectional view illustrating the internal structure and the interaction between the two lenses, and ( c ) Ray diagram depicting the refraction patterns and t... More about this image found in ( a ) Perspective 3D view of the double axicon lens, showing the arrangemen...

Fig. 11 Simulated beam formation by the double axicon lens showing the line focus along the optical axis: ( a ) 140 deg apex angle double axicon and ( b ) 160 deg apex angle double axicon. Axial pressure distribution: ( e ) 140 deg apex angle double axicon and ( f ) 160 deg apex angle double axico... More about this image found in Simulated beam formation by the double axicon lens showing the line focus a...

Fig. 12 Normalized line profiles of the transverse field distributions corresponding to spherical lens, single axicon, central flat axicon, and double axicons lens for 140 deg apex angle. Field profiles for single axicon and central flat axicon overlap each other. More about this image found in Normalized line profiles of the transverse field distributions correspondin...

Fig. 13 Broadband response of the single axicon, central flat axicon, and the double axicon lens More about this image found in Broadband response of the single axicon, central flat axicon, and the doubl...

Fig. 1 Schematic representation of the bent plate More about this image found in Schematic representation of the bent plate

Fig. 2 Bent plate validation results plots [ 39 ]: ( a ) scattering coefficients and ( b ) energy error More about this image found in Bent plate validation results plots [ 39 ]: ( a ) scattering coefficients a...

Fig. 3 90-deg bent plate with notch at introdos and extrados: ( a ) 90-deg notch and ( b ) semicircular notch More about this image found in 90-deg bent plate with notch at introdos and extrados: ( a ) 90-deg notch a...

Fig. 4 Coefficients of scattering for the A0 incident mode for a bent plate with a 90-deg notch More about this image found in Coefficients of scattering for the A0 incident mode for a bent plate with a...

Fig. 5 Coefficients of scattering for the S0 incident mode for a bent plate with a 90-deg notch More about this image found in Coefficients of scattering for the S0 incident mode for a bent plate with a...