Abstract
In this paper, different types of singular points of the wave vector surface are considered. It is demonstrated that the light and acoustic beam propagation along the directions related to these points is identified with the simplest diffraction catastrophes. The possibility of transformation of one type of catastrophes to another in the presence of small disturbance is established. To illustrate this, we show an example of removing the degeneracy of phase velocities along the optical (acoustic) axis in a gyrotropic crystal and transforming a diffraction catastrophe, consisting in the correspondence of one wave normal to the whole cone of rays, into a diffraction catastrophe of the fold. The latter is characterized by the formation of sharp edges and the allocation of an additional sub-surface on the ray surface. Owing to this, not two but four (in acoustics – quasi transversal) waves with different group velocities may propagate in a definite direction near the (acoustic) axis.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.