Nanosecond pressure pulse profile visualization based on the density dependence of the critical angle of total internal reflection

2001 ◽  
Author(s):  
Kunihito Nagayama ◽  
Sachiko Hatano ◽  
Yasuhito Mori ◽  
Mitsuru Terada ◽  
Yasuhiro Motegi ◽  
...  
Keyword(s):  
Density Dependence ◽  
Total Internal Reflection ◽  
Critical Angle ◽  
Pressure Pulse ◽  
Internal Reflection ◽  
Pulse Profile

Non-Intrusive Unilateral Measurements of Void Incidence Within a Microchannel

2007 ◽  
Author(s):  
Douglas Heymann ◽  
Jordan Young ◽  
Ruander Cardenas
Keyword(s):  
Data Acquisition ◽  
Light Beam ◽  
Void Fraction ◽  
Vapor Bubble ◽  
Total Internal Reflection ◽  
Critical Angle ◽  
Optical Probe ◽  
Internal Reflection ◽  
Continuous Data ◽  
Two Phase

Void fraction measurements are used to characterize two-phase flow within a microchannel. Limitations of typical void fraction measurement systems include disruption of the flow (intrusive optical probe) and non-continuous data acquisition. Using the principles of total internal reflection, a Non-Intrusive Void Incidence Sensor (NIVIS) has been developed to determine the void incidence (frequency of a vapor bubble passing a known position in the channel). Continuous data can be recorded with a typical computer. A light beam is introduced through a fiber optic to the outside of a transparent channel wall at a critical angle. This critical angle is designed such that when a vapor bubble is present at the specified location, total internal reflection will occur. An output fiber is fixed in a determined position to receive light in the case of total internal reflection. Without the presence of a vapor bubble, the light beam will be reflected past the output fiber. A substantial increase in output signal is noticed when total internal reflection occurs. Characteristics of the NIVIS, proven during non-intrusive testing, include: continuous data acquisition of bubble incidences, measurements within a 100 micron wide channel, and bubble boundary differentiation.

Microwave Phase Measurements Associated with the Goos–Hänchen Shift

1972 ◽  
Vol 50 (1) ◽  
pp. 52-56 ◽  
Author(s):  
L. Arthur ◽  
A. Read ◽  
I. R. Dagg ◽  
G. E. Reesor
Keyword(s):  
Satisfactory Agreement ◽  
Total Internal Reflection ◽  
Critical Angle ◽  
Detection Method ◽  
Microwave Energy ◽  
Internal Reflection ◽  
Phase Changes ◽  
Homodyne Detection ◽  
Phase Measurements ◽  
Made In

Microwave phase measurements, using the Robertson homodyne detection method, have been made in the field outside a dielectric prism after microwave energy has experienced total internal reflection. The phase changes that occur in this case are explained by extending Artmann's theory of the Goos-Hänchen effect to microwave optics. Satisfactory agreement between the theory and measurements has been obtained for angles of incidence from 40 to 50° on a dielectric boundary for which the critical angle is 36.4°.

scholarly journals Refractive Index Imaging of Cells with Variable-Angle Near-Total Internal Reflection (TIR) Microscopy

2017 ◽  
Vol 23 (5) ◽  
pp. 978-988 ◽  
Author(s):  
Kevin P. Bohannon ◽  
Ronald W. Holz ◽  
Daniel Axelrod
Keyword(s):  
Refractive Index ◽  
Total Internal Reflection ◽  
Critical Angle ◽  
Single Cells ◽  
Chinese Hamster Ovary Cells ◽  
Angular Position ◽  
Chinese Hamster ◽  
Internal Reflection ◽  
Index Of Refraction ◽  
Lateral Resolution

AbstractThe refractive index in the interior of single cells affects the evanescent field depth in quantitative studies using total internal reflection (TIR) fluorescence, but often that index is not well known. We here present method to measure and spatially map the absolute index of refraction in a microscopic sample, by imaging a collimated light beam reflected from the substrate/buffer/cell interference at variable angles of incidence. Above the TIR critical angle (which is a strong function of refractive index), the reflection is 100%, but in the immediate sub-critical angle zone, the reflection intensity is a very strong ascending function of incidence angle. By analyzing the angular position of that edge at each location in the field of view, the local refractive index can be estimated. In addition, by analyzing the steepness of the edge, the distance-to-substrate can be determined. We apply the technique to liquid calibration samples, silica beads, cultured Chinese hamster ovary cells, and primary culture chromaffin cells. The optical technique suffers from decremented lateral resolution, scattering, and interference artifacts. However, it still provides reasonable results for both refractive index (~1.38) and for distance-to-substrate (~150 nm) for the cells, as well as a lateral resolution to about 1 µm.

scholarly journals Ellipsometry of thin films of biological objects under conditions of total internal reflection

2022 ◽  
Vol 24 (4) ◽  
pp. 7-12
Author(s):  
Valeriy V. Yatsishen
Keyword(s):  
Thin Films ◽  
Total Internal Reflection ◽  
Critical Angle ◽  
High Efficiency ◽  
Polarized Light ◽  
Internal Reflection ◽  
Test Material ◽  
Angle Of Incidence ◽  
Film Material ◽  
Circularly Polarized

An analysis of the ellipsometric parameters of the reflected light from the prism test material air system is carried out when circularly polarized light is incident on it under the conditions of the onset of the phenomenon of total internal reflection. At the onset of total internal reflection, the ellipsometry parameter shows high variability with the angle of incidence, in contrast to the parameter r0. It is shown that TIR occurs when the angle of incidence is not equal to the critical angle of the adjacent media for two different materials, these angles differ from each other. In the case of a film, the TIR phenomenon occurs at an angle equal to the critical angle at the prism-air interface and does not depend on the film material. The results obtained show the high efficiency of using the ellipsometric method together with circularly polarized incident radiation for diagnostics of thin films made of biological material.

Total Internal Reflection Raman Spectroscopy at the Critical Angle for Raman Measurements of Thin Films

1981 ◽  
Vol 35 (6) ◽  
pp. 584-587 ◽  
Author(s):  
Reikichi Iwamoto ◽  
Koji Ohta ◽  
Masaru Miya ◽  
Seiichi Mima
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Total Internal Reflection ◽  
Critical Angle ◽  
Coating Layer ◽  
Signal Enhancement ◽  
Internal Reflection ◽  
Thin Coating ◽  
Polystyrene Film ◽  
Bovine Albumin

Total internal reflection Raman spectroscopy at the critical angle has been shown to be useful for Raman measurements of not only thin films but also of any samples that can be directly coated or intimately contacted on the internal reflection element (IRE). Usefulness of this technique was demonstrated for a polystyrene film (0.70 μm thick) coated on the IRE, signal enhancement being 40 as compared with the conventional normal illumination. The technique was also applied to a thin coating layer of bovine albumin on the IRE to give the spectrum of excellent signal/noise ratio.

A Demonstration of the Critical Angle Without Using Total Internal Reflection

2005 ◽  
Vol 43 (7) ◽  
pp. 471-472 ◽  
Author(s):  
Barret R. Viss ◽  
Arnold E. Sikkema
Keyword(s):  
Total Internal Reflection ◽  
Critical Angle ◽  
Internal Reflection

Microwave optical modulation by using the electro-optic effect in total internal reflection at the critical angle

1992 ◽  
Vol 17 (16) ◽  
pp. 1125 ◽  
Author(s):  
Douglas L. Butler ◽  
Chi H. Lee ◽  
H. J. Simon ◽  
Geoffrey L. Burdge
Keyword(s):  
Total Internal Reflection ◽  
Critical Angle ◽  
Internal Reflection ◽  
Optical Modulation ◽  
Electro Optic
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