Total external reflection

About: Total external reflection is a research topic. Over the lifetime, 829 publications have been published within this topic receiving 22213 citations.

Ellipsometry of anisotropic substrates: Re‐examination of a special case

Abstract: When the index of refraction of a bulk material is determined using ellipsometry, an erroneous result is obtained if the material is anisotropic, and we have assumed that it is isotropic. This is not surprising. What is surprising is that, in the case of a uniaxial material with its optic axis perpendicular to the surface, the apparent index of refraction obtained from ellipsometric measurements does not lie between the ordinary and extraordinary indices of refraction and is therefore not even a good estimate of the actual index of refraction experienced by light in the anisotropic material. In addition, even though the actual index of refraction experienced by the light depends on the angle of incidence, making ellipsometric measurements at different angles of incidence does not resolve this problem.

Reflection and Transmission of Sound by a Moving Medium

Abstract: The reflection and transmission of sound by a moving medium are investigated theoretically and the reflection and transmission coefficients are determined. These coefficients are found to depend only upon that component of the velocity of the medium which lies in the plane of incidence. The reflection coefficient increases with the velocity of the moving medium until a velocity is reached at which total reflection occurs. Total reflection persists until a still higher velocity is reached above which the reflection coefficient decreases as the velocity increases.

Broadband omnidirectional reflection from negative index materials

Abstract: We show, by using a dispersion relation with parameters taken from experimental data, that a single layer of a negative index material has omnidirectional reflection properties. In the range between the electric plasma frequency and the magnetic plasma frequency, the refractive index is close to zero and the negative index materials reflect radiation for all angles of incidence and polarization with reflectivities of ∼99%. In addition, with increasing angles of incidence, the reflecting band does not shift in frequency but actually widens. The operational bandwidth can be 100% or greater by increasing the separation between the electric and magnetic plasma frequencies.

Use of Frustrated Total Internal Reflection to Measure Film Thickness and Surface Reliefs

Abstract: When total internal reflection of light occurs, radiation penetrates beyond the reflecting surface into the rarer medium where the intensity decreases with distance from the interface in an exponential manner. Since the degree of coupling to this radiation can be controlled by adjusting the proximity of another object to this interface, it is possible to utilize this phenomenon in the measurement of film thickness and to obtain high contrast images of surface reliefs.

Refractive index measurement using total internal reflection

Abstract: An undergraduate level experiment is presented for demonstrating total internal reflection. The experiment yields a relatively precise value of the refractive index of a prism to be found from a measurement of the incident angle at which total internal reflection occurs. Analytic expressions are obtained for the refractive index as a function of the incident angle for both equilateral and right angle prisms. Students can observe not only the critical angle at which total internal reflection occurs, but measure and analyze the significant rise in reflected beam power. The addition of a small fluid reservoir attached to the side of the prism enables the determination of a liquid refractive index.