scispace - formally typeset
Search or ask a question

Showing papers on "Total internal reflection published in 2003"


Patent
26 Sep 2003
TL;DR: In this article, the authors proposed a semiconductor light emitting device including a substrate, and at least a first semiconductor layer, an active layer and a second semiconducting layer that are sequentially provided on the substrate.
Abstract: The refractive index of the material for forming a light emitting element, example of the material including a group III Nitride Compound Semiconductor, is relatively higher than that of air; therefore, in order to emit, into air, light generated in an active layer in conventional semiconductor light emitting devices, it is indispensable that its incidence angle from their semiconductor layer into the air is the critical angle of total reflection or less. If the incidence angle is more than the critical angle of total reflection, the light cannot go out into the air, and is totally reflected. In order to solve the problem, the invention is a semiconductor light emitting device including a substrate, and at least a first semiconductor layer, an active layer and a second semiconductor layer that are sequentially provided on the substrate, wherein the second semiconductor layer has a polarity different from that of the first semiconductor layer, and the total area of the first semiconductor layer, the active layer and the second semiconductor layer in side faces where the active layer is uncovered is 5% or more of the area of the upper face which is uncovered at the side of the second semiconductor layer.

753 citations


Patent
19 Mar 2003
TL;DR: In this paper, a light-transmitting substrate and a plurality of partially reflecting surfaces are carried by the substrate, characterized by the fact that the reflected surfaces are parallel to each other and are not parallel to any of the edges of the substrate.
Abstract: The invention provides an optical device, including a light-transmitting substrate, optical means for coupling light into the substrate by total internal reflection, and a plurality of partially reflecting surfaces carried by the substrate, characterized in that the partially reflecting surfaces are parallel to each other and are not parallel to any of the edges of the substrate.

365 citations


Journal ArticleDOI
TL;DR: It is found that when a light beam travels through a slab of optically denser dielectric medium in air, the lateral shift of the transmitted beam can be negative, a novel phenomenon that is reversed in comparison with the geometrical optic prediction according to Snell's law of refraction.
Abstract: It is found that when a light beam travels through a slab of optically denser dielectric medium in air, the lateral shift of the transmitted beam can be negative. This is a novel phenomenon that is reversed in comparison with the geometrical optic prediction according to Snell's law of refraction. A Gaussian-shaped beam is analyzed in the paraxial approximation, and a comparison with numerical simulations is made. Finally, an explanation for the negativity of the lateral shift is suggested, in terms of the interaction of boundary effects of the slab's two interfaces with air.

228 citations


Journal ArticleDOI
TL;DR: In this paper, an optical parametric oscillator and a YAG laser (1.064 μm) were used to extend the frequency region up to 7 THz.
Abstract: Following the generation of tunable terahertz waves from GaP in the 0.5- to 3-THz region, we extended the frequency region up to 7 THz, using an optical parametric oscillator and a YAG laser (1.064 μm). The tuning angle θin increased superlinearly in the 3- to 7-THz region, so that the total reflection took place at 5 THz, which was avoided by rotating the crystal relative to the incident optic axis. As a result, terahertz output peak powers of 100 mW at up to 5.6 THz and 3 mW at 7 THz were obtained, at pump and signal energies of 3 mJ, respectively.

215 citations


Journal ArticleDOI
TL;DR: Gaussian beams that undergo total internal reflection from a DNG metamaterial slab are shown to experience a negative Goos-Hänchen (lateral) shift and several potential applications for these effects in the microwave and optical regimes are discussed.
Abstract: The interactions of pulsed and continuous wave (CW) Gaussian beams with double negative (DNG) metatmaterials are considered. Subwavelength focusing of a diverging, normally incident pulsed Gaussian beam with a planar DNG slab is demonstrated. The negative angle of refraction behavior associated with the negative index of refraction exhibited by DNG metamaterials is demonstrated. The transmitted beam resulting from both 3- cycle and CW Gaussian beams that are obliquely incident on a DNG slab are shown to have this property. Gaussian beams that undergo total internal reflection from a DNG metamaterial slab are also shown to experience a negative Goos-Hanchen (lateral) shift. Several potential applications for these effects in the microwave and optical regimes are discussed.

205 citations


Journal ArticleDOI
TL;DR: In this article, the internal wave reflection from concave and convex slopes that pass through the critical angle was investigated numerically using the nonhydrostatic Massachusetts Institute of Technology General Circulation Model (MITgcm).
Abstract: Internal wave reflection from a sloping topographic boundary may lead to enhanced shear if the topographic angle to the horizontal is close to that of the internal wave group velocity vector. Previous analytic studies have suggested that shear enhancement is reduced at concave slopes as compared with convex and planar slopes near the critical angle. Here the internal wave reflection from concave and convex slopes that pass through the critical angle is investigated numerically using the nonhydrostatic Massachusetts Institute of Technology General Circulation Model (MITgcm). Overturning, shear instability, and resultant mixing are examined. Results are compared with simulations of wave reflection from planar slopes with angles greater than, less than, and equal to the critical angle. In contrast to the analytic predictions, no reduction in mixing is found for the concave slope as compared with the other slopes. In all cases, stratification is eroded in a band above the slope, bounded at its outer ...

176 citations


Patent
14 Jun 2003
TL;DR: In this paper, a touch panel in which two or more light sensors emit light into a transparent panel at an angle to sustain transmission through the panel by total internal reflection is described.
Abstract: A touch panel in which two or more light sensors emit light into a transparent panel at an angle to sustain transmission through the panel by total internal reflection. The transmitted light is detected at an array of light detection positions around the periphery of the panel opposite to each light source. When an object contact the surface of the panel, light transmitted along the pathway from a given source past the contact point to one of the detection points is attenuated by the frustrated total internal reflection (FTIR) effect. Each contact causes two or more intersecting light beams having known end points to be attenuated, enabling a connected processor to determine the position and size of the contact area.

164 citations


Journal ArticleDOI
TL;DR: In this paper, the optical near-field distributions of the surfaceplasmon (sp) modes sustained by the stripes were recorded using a photon scanning tunneling microscope (PSTM) for a fixed frequency of the incident light, these field distributions were found to depend on the width of the stripes.
Abstract: Thin gold stripes, featuring various widths in the micrometer range, were microfabricated to obtain surface-plasmon guides on a glass substrate. Each metal stripe (MS) was excited by an incident surface-plasmon polariton which was itself launched on an extended thin gold film by the total internal reflection of a focused beam coming through the substrate. The optical near-field distributions of the surface-plasmon (sp) modes sustained by the stripes were then recorded using a photon scanning tunneling microscope (PSTM). For a fixed frequency of the incident light, these field distributions are found to depend on the widths of the stripes. We first provide an experimental study of the various order modes which arise as a function of the decreasing width. Specifically, we show that the lateral confinement of a MS surface-plasmon mode is not related to a reflection of the SP on the edges of the stripe. On the basis of PSTM images recorded over a gold thin-film step discontinuity, we show that the metal stripe plasmon modes are hybrid modes created by the coupling of interface and boundary modes. Using MSs of various thicknesses, we finally demonstrate that, similarly to the symmetric mode of an extended metal thin film bounded by different dielectric media, the field of the MS modes is mostly localized at the interface between the metal and the dielectric medium with the lowest refractive index.

162 citations


Journal ArticleDOI
TL;DR: In this article, the velocity field measurements with this small out-of-plane spatial resolution (in all cases less than 380mm) are presented. But the results are in reasonable agreement with the exact solution for the corresponding single-phase Stokesian flow.
Abstract: Evanescent waves from the total internal reflection of a 488 nm argon-ion laser beam at a glass–water interface were used to measure velocity fields in creeping rotating Couette flow within 380 nm of the stationary solid surface. Images of fluorescent 300 and 500 nm diameter polystyrene and silica particles suspended in water recorded at 30 Hz were processed using cross-correlation particle image velocimetry to determine the two in-plane velocity components with an in-plane spatial resolution of 40×40 µm over a 200 µm (h)×150 µm (v) field of view. The results are in reasonable agreement with the exact solution for the corresponding single-phase Stokesian flow. These data are, to our knowledge, the first velocity field measurements with this small out-of-plane spatial resolution (in all cases less than 380 nm), and the first such measurements in this interfacial or near-wall region. This paper describes the novel experimental diagnostic technique used to obtain these results.

153 citations


Journal ArticleDOI
TL;DR: The novel compact illumination device in variable‐angle total internal reflection fluorescence microscopy (VA‐TIRFM) appears appropriate for numerous applications in which high axial resolution is required, e.g. time‐resolved fluorescence spectroscopy, fluorescence lifetime imaging (FLIM) or fluorescence resonance energy transfer (FRET).
Abstract: A novel compact illumination device in variable-angle total internal reflection fluorescence microscopy (VA-TIRFM) is described. This device replaces the standard condensor of an upright microscope. Light from different laser sources is delivered via a monomode fibre and focused onto identical parts of a sample under variable angles of total internal reflection. Thus, fluorophores in close proximity to a cell-substrate interface are excited by an evanescent wave with variable penetration depth, and localized with high (nanometre) axial resolution. In addition to quantitative measurements in solution, fluorescence markers of the cytoplasm and the plasma membrane, i.e. calcein and laurdan, were examined using cultivated endothelial cells. Distances between the glass substrate and the plasma membrane were determined using the mathematical algorithm of a four-layer model, as well as a Gaussian-shaped intensity profile of the illumination spot on the samples. Distances between 0 and 30 nm in focal contacts and between 100 and 300 nm in other parts of the cell were thus determined. In addition to measurements of cell-substrate topology, the illumination device appears appropriate for numerous applications in which high axial resolution is required, e.g. experiments on endocytosis or exocytosis, as well as measurements of ion concentrations proximal to the plasma membrane. The compact illumination device is also suitable for combining TIRFM with further innovative techniques, e.g. time-resolved fluorescence spectroscopy, fluorescence lifetime imaging (FLIM) or fluorescence resonance energy transfer (FRET).

139 citations


Journal ArticleDOI
TL;DR: In this article, the effect of total external reflection on metal-dielectric nanostructures is investigated when light from vacuum is incident onto these materials at an angle exceeding the critical angle defined by Snell's law.
Abstract: Metamaterials composed of metal-dielectric nanostructures are engineered to have an effective refractive index less than unity at optical wavelengths. The effect of total external reflection is demonstrated when light from vacuum is incident onto these materials at an angle exceeding the critical angle defined by Snell’s law. Novel approaches are discussed to derive the effective index of refraction from the reflection and refraction properties of finite slabs. The effect of losses and dispersion are analyzed in the visible range of frequencies by consideration of the measured properties of silver. The differences among ultralow refractive-index metamaterials, photonic bandgap materials, and metals are discussed. Remarkably, a bandgap is not required to obtain total external reflection.

Journal ArticleDOI
TL;DR: A theoretical investigation of the nonlinear interaction between an acoustic plane wave and an interface formed by two rough, nonconforming surfaces in partial contact is presented and attention is drawn to the enhanced nonlinear response of an interface insonified by a shear vertical wave in the neighborhood of the longitudinal critical angle.
Abstract: A theoretical investigation of the nonlinear interaction between an acoustic plane wave and an interface formed by two rough, nonconforming surfaces in partial contact is presented. The macroscopic elastic properties of such a nonlinear interface are derived from micromechanical models accounting for the elastic interaction that is characteristic of spherical bodies in contact. These results are used to formulate set of boundary conditions for the acoustic field, which are to be enforced at the imperfect interface. The scattering problem is solved for plane wave incidence by using a simple perturbation approach and the harmonic balance method. Sample results are presented for arbitrary wave polarization and angle of incidence. The relative magnitude of the nonlinear signals and their potential use toward the nondestructive evaluation of imperfect interfaces are assessed. In particular, attention is drawn to the enhanced nonlinear response of an interface insonified by a shear vertical wave in the neighborhood of the longitudinal critical angle. The motivation for this investigation is provided by the need to develop nondestructive methods to detect and localize small, partially closed cracks in metals with coarse microstructures.

Patent
13 Jun 2003
TL;DR: In this article, an optical element has a plurality of clusters, shaped along the x-, y-and z-axis to control the light distribution of a small LED light source.
Abstract: An LED signal using a novel optical element to control the light distribution of a small LED light source. Light emitted by the LEDs illuminates the optical element. The optical element has a plurality of clusters, shaped along the x-, y- and z-axis to control the light. After the light is distributed, it encounters a second optical surface of the optical element, typically a fresnel surface. The light is controlled by the optical element. Optionally, a lens can be placed over each LED to control the light pattern of the LED. The lens has an entry face to direct the light to a total internal reflection surface on the side, which redirects the light to the exit face. The resulting signal is a uniform, efficient signal.

Journal ArticleDOI
H.-P. Lehr1, Reimann M1, Albrecht Brandenburg1, Sulz G1, Klapproth H1 
TL;DR: The development of an optical readout system for the real-time analysis of fluorescent-labeled DNA microarrays is described, targeted toward research applications in genomics, agriculture, and life sciences, where the end-point detection of state-of-the-art readout systems does not provide sufficient information on the hybridization process.
Abstract: This paper describes the development of an optical readout system for the real-time analysis of fluorescent-labeled DNA microarrays is described. The system is targeted toward research applications in genomics, agriculture, and life sciences, where the end-point detection of state-of-the-art readout systems does not provide sufficient information on the hybridization process. The hybridization progress of molecules from the liquid phase in a flow cell to immobilized oligonucleotides on a transducer surface can be observed. The excitation of fluorochromes is realized by a semiconductor laser, and the fluorescence emission is collected by a cooled CCD camera. Quantitative data can be extracted from the images for analysis of the microarray. For the signal transduction, the principle of total internal reflection is used. With a multiple internal reflection arrangement, the sensor chip was adapted to the standard microscope slide format and a homogeneous evanescent illumination of the active area of the senso...

Journal ArticleDOI
Suntak Park1, Gwansu Lee1, Seok Ho Song1, Cha-Hwan Oh1, Pill Soo Kim1 
TL;DR: The dielectric gratings, which have a surface-relief structure with only several tens of nanometers in peak-to-trough height on a flat metal surface, can efficiently extract radiation modes propagating in free space from the surface-plasmon modes.
Abstract: Efficient outcoupling of surface-plasma waves to radiation modes by use of dielectric diffraction gratings on a flat metallic surface is discussed. The dielectric gratings, which have a surface-relief structure with only several tens of nanometers in peak-to-trough height on a flat metal surface, can efficiently extract radiation modes propagating in free space from the surface-plasmon modes. An outcoupling efficiency of 50% is estimated with the rigorous coupled-wave diffraction theory, and it is confirmed by the experiment.

Patent
26 Feb 2003
TL;DR: A reflective display with a plurality of approximately hemispherical high refractive index is considered in this paper, where a member is selectably moved into an intense evanescent wave region at the hemi-beads' inward side to selectably frustrate substantial total internal reflection of light rays.
Abstract: A reflective display (10) having a plurality of approximately hemispherical high refractive index (.eta.1) transparent hemi-beads (14) substantially covering and protruding inwardly from a transparent sheet's (12) inward surface. The transparent sheet, which has an outward viewing surface (17), has a refractive index (.eta.2) which can be low (i.e. .eta.1.apprxeq.1.92 and .eta.2.apprxeq.1.59). A member is selectably moved into an intense evanescent wave region at the hemi-beads' inward side to selectably frustrate substantial total internal reflection of light rays. The member can be a plurality of light scattering particles (26) suspended in a low refractive index (.eta.3.apprxeq.1.27) electrophoresis medium (20) and electrophoretically moved into or out of the intense evanescent wave region.

Journal ArticleDOI
TL;DR: In this paper, a common-path, heterodyne interferometric system for investigation of the phase variations under surface plasmon resonance (SPR) is presented, which utilizes a pair of orthogonally linearly polarized beams with heterodyn frequency of 60 kHz as the light source.
Abstract: A common-path, heterodyne interferometric system for investigation of the phase variations under surface plasmon resonance (SPR) is presented. With the combination of SPR and total internal reflection (TIR), the system has the merits of avoiding direction change in the output light and increasing sensitivity. The system utilizes a pair of orthogonally linearly polarized beams with heterodyne frequency of 60 kHz as the light source. Because the two beams are perfectly collinear, the noises resulting from the ambient conditions are greatly reduced. Compared to reflectivity variation measurement, which is widely used in traditional SPR, the phase variation measurement using common-path, heterodyne techniques is approximately an order of magnitude higher in sensitivity and thus can be used as a high-sensitivity-demanded biosensor.

Patent
24 Apr 2003
TL;DR: In this paper, a diffractive optical element comprising a linear grating was formed in a light-transmissive substrate, which is characterized by a pitch, d, selected so as to allow total internal reflection of a light having wavelength λB and a striking angle of α -FOV.
Abstract: A diffractive optical element (10) for guiding a light having a color spectrum characterized by a plurality of wavelengths longer than a shortest wavelength, λ B, and shorter than a longest wavelength λ R, the light striking the diffractive optical element (10) at an angle greater than a first field-of-view angle, α-FOV, and smaller than a second field-of-view angle, α+FOV. The diffractive optical element comprising a linear grating (12) being formed in a light-transmissive substrate (14). The linear grating (12) is characterized by a pitch, d, selected so as to allow total internal reflection of a light having wavelength λB and a striking angle of α -FOV. The light-transmissive substrate is characterized by an index of refraction, ηS, larger than a minimal index of refraction, ηmin, which is selected so as to allow total internal reflection of a light having wavelength of λR and a striking angle of α +FOV.

Journal ArticleDOI
TL;DR: In this paper, a three-dimensional tungsten photonic crystal is thermally excited and shown to emit light at a narrow band, λ = 3.3-4.25 μ m.
Abstract: A three-dimensional tungsten photonic crystal is thermally excited and shown to emit light at a narrow band, λ = 3.3–4.25 μ m . The emission is experimentally observed to exceed that of the free-space Planck radiation over a wide temperature range, T = 475–850 K . It is proposed that an enhanced density of state associated with the propagating electromagnetic Bloch waves in the photonic crystal is responsible for this experimental finding.

Patent
25 Feb 2003
TL;DR: A compound polarization beam splitter for use with a reflective, polarization-modulating, imaging device, e.g., a LCoS device, is provided in this paper.
Abstract: A compound polarization beam splitter (33) for use with a reflective, polarization-modulating, imaging device (10), e.g., a LCoS device, is provided. The compound PBS has: (a) an input prism (20); (b) an output prism (30), and (c) a polarizer (13), which is located between the two prisms (20,30) and which may be a wire grid polarizer (13a) or a multi-layer reflective polarizer (13b). Polarized illumination light (11) enters the input prism (20) through a first surface (21) and undergoes total internal reflection at a second surface (22) before being reflected from the polarizer (13) and polarization-modulated at the imaging device (10). The polarizer's tilt angle (β) is less than 45°, which reduces astigmatism and the required back working distance of the system's projection lens (74).

Patent
22 Oct 2003
TL;DR: In this article, the authors propose a diffractive structure for responding to incident radiation, which consists of a substrate having a diffuse surface and a coating layer disposed over the diffractive surface, the coating layer having an index of refraction substantially different from that of the substrate.
Abstract: A diffractive structure for responding to incident radiation includes a substrate having a diffractive surface and a coating layer disposed over the diffractive surface, the coating layer having an index of refraction substantially different from that of the substrate. The diffractive surface comprises a three-dimensional pattern selected to diffract incident radiation with substantial efficiency into one or more diffraction orders other than the first order and to redirect the diffracted radiation from the structure in at least two directions at angles that are greater than a critical angle required for total internal reflection. In application of the diffractive structure to solar cell modules, a diffractive structure disposed in spaces between plural solar cells redirects incident radiation from the area within the spaces onto the solar cells, thus concentrating solar radiation onto the cells.

Journal ArticleDOI
TL;DR: An analysis of the guiding and antiguiding properties of the PCF for acoustic waves is presented, finding that the subpeaks are caused by an interaction between light-wave and guided modes of longitudinal acoustic waves in the graded-Ge-doped region, the silica region, and the microstructured cladding.
Abstract: The Brillouin scattering spectrum in a photonic crystal fiber (PCF) with a partially Ge-doped core is measured with a pump–probe technique at a wavelength of 1320 nm. One main peak and four subpeaks are observed. The main peak has a Lorentzian shape with the bandwidth ΔνB=66MHz . Its intensity is six times higher than that from a standard single-mode fiber measured under the same conditions, which is consistent with the ratio of (1/APCFeff) /(1/ASMFeff) , where Aeff is the effective area of the fibers. The temperature coefficient for the main peak is 0.96 MHz/ °C. We believe that the subpeaks are caused by an interaction between light-wave and guided modes of longitudinal acoustic waves in the graded-Ge-doped region, the silica region, and the microstructured cladding. An analysis of the guiding and antiguiding properties of the PCF for acoustic waves is presented.

Patent
28 May 2003
TL;DR: In this article, a non-sealing type light emitting element having a diode structure formed by laminating an n-type semiconductor layer and a p-type layer on one surface of a translucent substrate, wherein the outside surface of the translucent substrate is tilted and made non-parallel with respect to the outermost-side surface of diode structures so as to enhance a light picking up efficiency from the outgoing surface of light.
Abstract: A non-sealing type light emitting element having a diode structure formed by laminating an n-type semiconductor layer and a p-type semiconductor layer on one surface of a translucent substrate, wherein the outside surface of the translucent substrate is tilted and made non-parallel with respect to the outer-most-side surface of the diode structure so as to enhance a light picking up efficiency from the outgoing surface of light. While a total reflection off these two surfaces is repeated, the incident angle of a light flux incident to the outgoing surface of light is gradually decreased to below a critical angle to allow the light flux to be output to the outside of the light emitting element.

Journal ArticleDOI
TL;DR: A micro-genetic algorithm with a 2-D finite difference time domain (FDTD) method is used to rigorously design high efficiency waveguide bends composed of multiple air trenches for 90 degrees bends and beamsplitters for waveguide material systems that have low refractive index and lowRefractive index contrast between the core and clad materials.
Abstract: We explore the use of air trenches to achieve compact high efficiency 90° waveguide bends and beamsplitters for waveguide material systems that have low refractive index and low refractive index contrast between the core and clad materials. For a single air interface, simulation results show that the optical efficiency of a waveguide bend can be increased from 78.4% to 99.2% by simply decreasing the bend angle from 90° to 60°. This can be explained by the angular spectrum of the waveguide mode optical field. For 90° bends we use a micro-genetic algorithm (µGA) with a 2-D finite difference time domain (FDTD) method to rigorously design high efficiency waveguide bends composed of multiple air trenches. Simulation results show an optical efficiency of 97.2% for an optimized bend composed of three air trenches. Similarly, a single air trench can be designed to function as a 90° beamsplitter with 98.5% total efficiency.

Patent
19 Nov 2003
TL;DR: In this article, a projection display device using a mirror array element as a light valve is used to thin the display by bending two reflection mirrors and making incident on a total reflection prism, and the reflection surface of the reflection mirror near the total prism is installed in parallel with the optical axis of a projection lens.
Abstract: PROBLEM TO BE SOLVED: To thin a projection display device using a mirror array element as a light valve and to make luminance higher by improving the light utilization efficiency in the display device. SOLUTION: Illumination light to illuminate the mirror array element is bent by two reflection mirrors and made incident on a total reflection prism, and the reflection surface of the reflection mirror near the total reflection prism is installed in parallel with the optical axis of a projection lens or at the angle within 10 degrees, so that the display device is thinned. By setting the mutual angles of the two reflection mirrors, an illumination area is accurately aligned with the image area of the mirror array element, and the luminance can be made higher by improving the light utilization efficiency. COPYRIGHT: (C)2004,JPO

Journal ArticleDOI
TL;DR: In this article, the effect of impact velocities on the electrical current generated by impact of particles on an inclined or rotating metal target was measured for various impact angles by changing the tangential or normal component of impact velocity.

Patent
08 May 2003
TL;DR: In this paper, a total internal reflection element is manufactured by injection molding, having a plurality of total internal reflections faces and exit faces which redirect light from a light source into a side direction.
Abstract: A total internal reflection element having a plurality of total internal reflection faces and a plurality of exit faces which redirect light from a light source into a side direction. The total internal reflection element is manufactured by injection molding. The curved entry faces have the optical effect of concentrating incident light onto a center of the corresponding total internal reflection face. This allows light impinging on the total internal reflection face from a wider range of angles to be redirected for side projection through the desired exit face. The total internal reflection element is used in a signal. The signal has a housing and can be placed at a variety of heights.

Journal ArticleDOI
TL;DR: The reflection and refraction of light is analyzed, and the expression for the Goos-Hänchen shifts of a Gaussian beam incident on a lower-index medium, both active and absorptive is derived.
Abstract: Totally internal reflected beams can be amplified if the lowerindex medium has gain. We analyze the reflection and refraction of light, and analytically derive the expression for the Goos-Hanchen shifts of a Gaussian beam incident on a lower-index medium, both active and absorptive. We examine the energy flow and the Goos-Hanchen shifts for various cases. The analytical results are consistent with the numerical results. For the TE mode, the Goos-Hanchen shift for the transmitted beam is exactly half of that of the reflected beam, resulting in a "1/2" rule.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the interferometric nature of the signal delivered by an apertureless scanning near-field optical microscope (SNOM) and showed that the detected signal can describe the complex field amplitude, or the field intensity, or a subtle mix of both, depending on the tip environment and the tip position.
Abstract: We investigate in detail the interferometric nature of the signal delivered by an apertureless scanning near-field optical microscope (SNOM). This nature is first brought to the fore by near-field images of an integrated waveguide. The detection process of an evanescent wave generated by total internal reflection is then studied by both lateral near-field scans and signal detection as a function of the tip-to-sample distance. This study permits interpretation of fringe patterns appearing in apertureless SNOM images and provides important information about the nature of the signal. In particular, both experimental data and simple calculations show that, because of interference with background light coming from the sample, the detected signal can describe the complex field amplitude, or the field intensity, or a subtle mix of both, depending on the tip environment and the tip position.

Journal ArticleDOI
TL;DR: In this article, a technique combining ellipsometry with total internal reflection (TIRE) is presented for measuring adsorption on metal surfaces in opaque liquids, which is suitable for monitoring of internal surfaces.
Abstract: A technique combining ellipsometry with total internal reflection is presented. The method is called total internal reflection ellipsometry (TIRE) and is suitable for monitoring of internal surfaces which opens new possibilities for measuring adsorption on metal surfaces in opaque liquids. Results from measurements of adsorption of milk and subsequent cleaning with sodium hydroxide on metal surfaces are given. These include studies on gold, iron, and chromium surfaces. A schematic design of the instrument used in TIRE is included. The main advantages of the system are non-invasive probing, fast response, and high sensitivity. The method has potential for applications in monitoring of internal surfaces of pipelines in industrial processes.