optyka: Total internal reflection

Evidence: 100 • authority: 72

In physics, total internal reflection (TIR) is the phenomenon in which waves arriving at the interface (boundary) from one medium to another (e.g., from water to air) are not refracted into the second ("external") medium, but completely reflected back into the first ("internal") medium. It occurs when the second medium has a higher wave speed (i.e., lower refractive index) than the first, and the waves are incident at a sufficiently oblique angle on the interface. For example, the water-to-air surface in a typical fish tank, when viewed obliquely from below, reflects the underwater scene like a mirror with no loss of brightness (Fig. 1). A scenario opposite to TIR, referred to as total exte…

Evidence: 65 • authority: 92

Horizontal tunneling of sound in three-dimensional idealized curved nonlinear internal wave ducts.. Nonlinear internal waves (NIWs) in the ocean can produce substantial effects on acoustic propagation, including three-dimensional reflection, refraction, and diffraction in the sound ducts bounded and formed by individual NIWs. Feature models for analyzing such effects frequently use a well approximation, which neglects the finite width of NIWs. This paper examines consequences of more realistic conditions including finite wave width and curvature. This curved duct model produces acoustic horizontal modes in the radial direction with a distinct characteristic of enhanced horizontal tunneling…

Evidence: 59 • authority: 72

Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves. The law of reflection says that for specular reflection (for example at a mirror) the angle at which the wave is incident on the surface equals the angle at which it is reflected. In acoustics, reflection causes echoes and is used in sonar. In geology, it is important in the study of seismic waves. Reflection is observed with surface waves in bodies of water. Reflection is observed with many types of electromagnetic wave, besides visible light. Reflectio…

Evidence: 47 • authority: 72

Specular reflection, or regular reflection, is the mirror-like reflection of waves, such as light, from a surface. The law of reflection states that a reflected ray of light emerges from the reflecting surface at the same angle to the surface normal as the incident ray, but on the opposing side of the surface normal. The incident and reflected rays lie in a plane known as the plane of incidence. The angles of the two rays to the normal are known as the angle of incidence and angle of reflection. The earliest known description of this behavior was recorded by Hero of Alexandria (AD c. 10–70). Later, Alhazen gave a complete statement of the law of reflection. He was first to state that the in…

Evidence: 42 • authority: 92

The damage potential of near-wall shock waves from cavitation bubbles investigated via total internal reflection fluorescence imaging.. This study establishes total internal reflection fluorescence (TIRF) imaging as a diagnostic method for investigating shock waves generated by collapsing laser-induced cavitation bubbles near a solid-liquid interface. TIRF was combined with synchronized short-pulse transillumination to capture both near-wall shock signatures and conventional bubble dynamics. A temperature-compensating Rhodamine 6G/Rhodamine B mixture made fluorescence variations primarily sensitive to density- and refractive-index changes. By tuning the laser incidence angle relative to the…

Evidence: 42 • authority: 92

Dual-physics programmable metasurfaces for dynamical controls of acoustics and electromagnetics.. Programmable metasurfaces bring new opportunities for modern acoustic and electromagnetic technologies by dynamically tailoring wave-matter interactions at subwavelength scales. Due to differences in physical properties and tuning mechanisms of acoustic and electromagnetic waves, current programmable metasurfaces typically manipulate only one type of wave, while concurrent and programmable controls of both waves remain elusive. Here, we propose a dual-physics programmable metasurface capable of simultaneous, independent and dynamic manipulations of acoustic and electromagnetic waves. The presen…

Evidence: 36 • authority: 80

Total Internal Reflection Velocimetry

Evidence: 36 • authority: 72

Reflection seismology (or seismic reflection) is a method of exploration geophysics that uses the principles of seismology to estimate the properties of the Earth's subsurface from reflected seismic waves. The method requires a controlled seismic source of energy, such as dynamite or Tovex blast, a specialized air gun or a seismic vibrator. Reflection seismology is similar to sonar and echolocation.

Evidence: 36 • authority: 80

Total internal reflection Terahertz imaging

Evidence: 36 • authority: 92

A Hybrid Metamaterial for Broadband, High-Performance Sound Absorption via Helmholtz Resonators Incorporating Porous Media.. Finite-thickness acoustic absorbers often face a trade-off between low-frequency resonance and broadband dissipation. The porous material (PR) provides stable mid-to-high-frequency losses through viscous and thermal effects, whereas Helmholtz resonators (HRs) offer compact low-frequency resonance but usually operate over narrow bands. Accordingly, an HR-PR hybrid metamaterial absorber is developed by coupling a central air neck and a sealed back cavity with a surrounding porous layer described by the Johnson-Champoux-Allard (JCA) rigid-frame equivalent-fluid model. A…

Evidence: — • authority: 72

Polarization, or polarisation, is a property of transverse waves which specifies the geometrical orientation of the oscillations. In a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the wave. One example of a polarized transverse wave is vibrations traveling along a taut string, for example, in a musical instrument like a guitar string. Depending on how the string is plucked, the vibrations can be in a vertical direction, in a horizontal direction, or any direction in between. In contrast, in longitudinal waves, such as sound waves in a liquid or gas, the displacement of the particles in the oscillation is always in the direction of propagat…

Evidence: — • authority: 72

A firearm is any type of gun that shoots projectiles using high explosive pressure generated from combustion (deflagration) of chemical propellant, most often black powder in antique firearms and smokeless powder in modern firearms. Small arms is a subset of light firearms that is designed to be readily carried and operated by an individual. The term "firearm" is however variably defined both technically and legally in different countries (see legal definitions), and can be used colloquially (sometimes incorrectly) to refer to any type of guns including air guns. The first firearms originated in 10th-century Song dynasty China (see gunpowder weapons in the Song dynasty), when bamboo tubes c…