Gaussian Beam Theory and Transducer Modeling

Keyword(s):  
Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 83
Author(s):  
Rocío Pérez de Prado ◽  
Sebastián García-Galán ◽  
José Enrique Muñoz-Expósito ◽  
Adam Marchewka

Multiple laser beams and single-mode optical fibers output can be approximated by assuming that the emitted light has a symmetrical Gaussian intensity profile, which corresponds to the transverse electromagnetic mode (TEM00), which is designated as a Gaussian beam. Current free-accessible design tools are limited to the spatial analysis of the beams, in general, and to the intensity, in particular, and to the graphical visualization in 2D with very limited options. In this work, a novel a computer-aided laser-fiber output beam TEM00 designer, CATEM00, is presented based on the 3D representations typically provided by camera beam profilers, and on the fundamentals of the wave theory of light, including diverse flexibility capabilities for graphical manipulation and parameter comprehension both in terms of spatial behavior and in angular confinement. It must be highlighted that not only is the spatial limitation design of light impact relevant in TEM00 applications but, also, the angle with which the light reaches the target. Hence, the availability of capabilities of phase design in TEM00 following the paraxial limitations is highly convenient. Results and discussion in terms of intensity, power, divergence and wave fronts are presented considering a set of study cases, showing its coherence with Gaussian beam theory.


1997 ◽  
Vol 188 (3) ◽  
pp. 273-279 ◽  
Author(s):  
C. J. DE GRAUW ◽  
N. M. SIJTSEMA ◽  
C. OTTO ◽  
J. GREVE

Author(s):  
K. Kuroda ◽  
Y. Tomokiyo ◽  
T. Kumano ◽  
T. Eguchi

The contrast in electron microscopic images of planar faults in a crystal is characterized by a phase factor , where is the reciprocal lattice vector of the operating reflection, and the lattice displacement due to the fault under consideration. Within the two-beam theory a planar fault with an integer value of is invisible, but a detectable contrast is expected when the many-beam dynamical effect is not negligibly small. A weak fringe contrast is also expected when differs slightly from an integer owing to an additional small displacement of the lattice across the fault. These faint contrasts are termed as many-beam contrasts in the former case, and as ε fringe contrasts in the latter. In the present work stacking faults in Cu-Al alloys and antiphase boundaries (APB) in CuZn, FeCo and Fe-Al alloys were observed under such conditions as mentioned above, and the results were compared with the image profiles of the faults calculated in the systematic ten-beam approximation.


1980 ◽  
Vol 41 (8) ◽  
pp. 837-844 ◽  
Author(s):  
F. Rohart ◽  
B. Macke
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document