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Light
Published in David M. Scott, Industrial Process Sensors, 2018
A prism (Figure 4.2b) is a wedge of glass or other transparent material. As Newton demonstrated in the seventeenth century, a prism can separate white light into its component colors. The explanation is that the speed of light in the prism depends on wavelength (see the discussion of dispersion at the end of section 3.3). When a beam of light strikes the prism at an angle, it is refracted according to Snell’s Law (equation 3.16), in which the index of refraction varies with wavelength. The result is that the light rays are bent; blue light has the higher index of refraction and is therefore refracted through a larger angle than red light. Reflective prisms (not shown in the figure) are also used in optical imaging systems to invert images or to reflect light.
Prisms
Published in Abdul Al-Azzawi, Light and Optics, 2018
Prisms are widely used in building optical devices, such as a prism spectrometer, which is commonly used to study the wavelengths emitted by a light source. Prisms are also used in building optical fibre devices, such as an opt-mechanical switch, which deflects or deviates an optical signal through a telecommunication system. Prisms can invert or rotate an image, deviate a light beam, disperse light into its component wavelengths, and separate states of polarization. The orientation of a prism (with respect to the incident light beam) determines its effect on the beam. Prisms can be designed for specific applications. The most popular prisms are right angle prisms, Brewster’s angle dispersing prisms, Penta prisms, solid glass retro-reflectors, equilateral dispersing prisms, littrow dispersion prisms, wedge prisms, roof prisms, and Dove prisms. Some of these commonly used prisms are discussed in detail in this chapter.
Diffraction
Published in Rajpal S. Sirohi, Optical Methods of Measurement, 2018
Prisms function as both reflective and refractive components. When used as dispersive elements in spectrographs and monochromators, prisms function purely as refractive components. However, when used for bending and splitting of beam, they use both refraction and reflection. As an example, we consider a right-angle prism, which can be used to bend rays by 90° or by 180°, as shown in Figure 3.5.
Design of an RGB colour separation prism based on the maximum ratio of aperture to length
Published in Journal of Modern Optics, 2023
Yunfeng Jiang, Dongsheng Wu, Bing Zhou, Jie Liu, Fuyu Huang
The effective transmission of light inside the prism requires total internal reflection. In this work, the prism material considered is glass ‘K9’ with n = 1.51630 and a total reflection angle . Figure 4 shows that the total internal reflection of the blue and red light occurs on the colour separation surfaces. and are, respectively, the half-field angles of the blue and red light determined by the total internal reflection. The green light is not restricted by this consideration. Therefore, we obtain: where,
Steering light in fiber-optic medical devices: a patent review
Published in Expert Review of Medical Devices, 2022
Merle S. Losch, Famke Kardux, Jenny Dankelman, Benno H. W. Hendriks
Another optical component that can be added outside the optical fiber to steer a light beam is a lens, as described in twelve patents [26,33,57–66]. A lens redirects a light beam due to refraction, changing its angular distribution. Lenses can be divided into converging and diverging lenses. In six devices, the distal tip includes a converging lens [26,33,57–60]. These converging lenses can be semi-spherical [57,58] or convex lenses [26,33,58–60]. In most standard designs, a converging lens focuses a light beam on a specific tissue area [26,33,57–60], see Figure 2j. The same converging lens can also collect light from this specific tissue area to one or more collecting fibers [33,57]. Smith [60] describes a special design including a converging lens and a faceted surface. The faceted surface receives light from the optical fiber and refracts it into different beam elements, which are then focused into multi-spots by a convex lens. In six devices, the distal tip includes a diverging lens [61–66]. This can be a semi-spherical [61–63], gradient-index [64], or concave [65] lens. Diverging lenses illuminate a wide area in the tissue. Nagale et al. [66] describe a special type of diverging lens, which is a triangular prism. The distal tip of this device consists solely of a prism that is directly coupled to the optical fiber. A light beam entering the prism refracts at the first face and then refracts again at the second face. As a result, light is emitted radially with a wide angular distribution. The prism can also rotate, allowing light to be emitted into the tissue in a 360° range, see Figure 2k.
Research on the passive nuclear level gauge
Published in Radiation Effects and Defects in Solids, 2019
Xi-Cheng Xie, Yuan-Yuan Zhang, Ya-Juan Guo, Wan-Chang Lai
The simulation object in the article is the commonly used electrostatic precipitator hopper in the thermal power industry and four passive nuclear level gauge. There are two main types: four prism type and quadrangular frustum pyramid type. This paper establishes a model of quadrangular frustum pyramid type hopper (Table 1), which dust flow is 50 t/h, the bottom size is 400 mm × 400 mm and 4800 mm in height. The hopper is made of typical reinforced steel structure, the outer surface of the hopper’s four side plates weld with reinforcing rib which is made of channel steel, angle steel. The reinforcing rib model is Q235A. The four passive nuclear level gauge are located on the right side of the hopper from which bottom to the top is NO.1 passive level gauge (low-level passive level gauge), NO.2 passive level gauge, NO.3 passive level gauge (high-level passive level gauge), NO.4 passive level gauge, respectively. The location height of the four passive nuclear level gauge is 90, 180, 270 and 360 cm, respectively.