#### Event Title

Nonspecular reflection of rotationally symmetric Gaussian beams from shaped fluid-solid interfaces

#### Location

La Jolla, CA

#### Start Date

1-1-1993 12:00 PM

#### Description

Nonspecular reflection, which occurs when an incident beam is phase matched to a leaky wave, is an important tool for fluid-solid interface diagnostics. A recently developed complex ray analysis for modeling nonspecular reflection of two-dimensional Gaussian sheet beams [1,2] is here extended to account for rotationally symmetric three-dimensional (3D) Gaussian beams (GBs) with arbitrary collimation. As in our 2D analysis, we utilize the complex-source-point (CSP) technique by which a conventional point-source-excited field can be converted into a 3D quasi-Gaussian beam field by displacing a real point source to a complex location [3]. When the CSP field excited in the fluid interacts with a plane or cylindrically layered elastic medium, the resulting internal and external fields can be expressed rigorously in terms of wavenumber spectral integrals that are approximated explicitly by high-frequency uniform asymptotics [4]. The resulting expressions for the reflected field contain interacting specularly reflected beam and leaky wave contributions which establish the physical basis for the observed phenomena.

#### Book Title

Review of Progress in Quantitative Nondestructive Evaluation

#### Volume

12A

#### Chapter

Chapter 1: Development of Standard Techniques

#### Section

Elastic Wave Propagation

#### Pages

187-194

#### DOI

10.1007/978-1-4615-2848-7_23

#### Copyright Owner

Springer-Verlag US

#### Copyright Date

January 1993

#### Language

en

#### File Format

application/pdf

Nonspecular reflection of rotationally symmetric Gaussian beams from shaped fluid-solid interfaces

La Jolla, CA

Nonspecular reflection, which occurs when an incident beam is phase matched to a leaky wave, is an important tool for fluid-solid interface diagnostics. A recently developed complex ray analysis for modeling nonspecular reflection of two-dimensional Gaussian sheet beams [1,2] is here extended to account for rotationally symmetric three-dimensional (3D) Gaussian beams (GBs) with arbitrary collimation. As in our 2D analysis, we utilize the complex-source-point (CSP) technique by which a conventional point-source-excited field can be converted into a 3D quasi-Gaussian beam field by displacing a real point source to a complex location [3]. When the CSP field excited in the fluid interacts with a plane or cylindrically layered elastic medium, the resulting internal and external fields can be expressed rigorously in terms of wavenumber spectral integrals that are approximated explicitly by high-frequency uniform asymptotics [4]. The resulting expressions for the reflected field contain interacting specularly reflected beam and leaky wave contributions which establish the physical basis for the observed phenomena.