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Radiometric and Photometric Measurements
Published in Lazo M. Manojlović, Fiber-Optic-Based Sensing Systems, 2022
Radiometry is the substantial part in the field of optical measurement and engineering, where the measurement techniques for power, polarization, spectral content, and other relevant parameters for an electromagnetic radiation interrogation, which are important in characterization of optical sources and detectors, have been studied. An instrument that measures optical radiation is named a radiometer. Radiometer is typically used to detect the radiation and in many applications, where it is essential, to measure the amount of the captured radiation. As a matter of fact, the word “radiometry” itself means the radiation measurement. The term radiometer is usually exclusively applied to the devices that measure radiance. However, this term will be used in a more general sense for a device that measures one of several power-dependent optical quantities. For example, radiance, defined as the optical power emitted from an area within particular solid angle, is one of many optical terms that will be defined and treated in this chapter. Moreover, this chapter will include both the corresponding mathematical techniques for calculating the radiative transfer as well as the measurement techniques for characterizing of fluxes and radiometric properties of different kinds.
Radiation Hazards
Published in Dag K. Brune, Christer Edling, Occupational Hazards in the Health Professions, 2020
The acronym “LASER” (light amplification by stimulated emission of radiation) is commonly applied to devices that emit an intense, coherent, directional beam of “light”. This very special type of optical radiation is a result of a process whereby an electron or molecule undergoes a quantum jump from a higher to a lower energy state, causing a spatially and temporarily coherent beam of light to be emitted. The extremely collimated character and generally high degree of monochromaticity of the LASER beam make this device of potential value in the treatment of the eye and skin, in various diagnostic techniques, in surgery of the skin and internal organs and in dentistry, enamel scaling, bridgework, etc.
Introductory Topics
Published in Riadh W. Y. Habash, Electromagnetic Fields and Radiation, 2018
An obvious division between the noncoherent optical radiation region and RFR region occurs at wavelengths of approximately 1 mm. The optical radiation is the other part of the EM spectrum to which human eyes respond. It is mainly divided into UV and infrared (IR) radiation.
Evaluating the blue-light hazard from solid state lighting
Published in International Journal of Occupational Safety and Ergonomics, 2019
John D. Bullough, Andrew Bierman, Mark S. Rea
Optical radiation, including visible, infrared and UV energy, can damage the retina in three possible ways [49]: (a) mechanical damage from intense pulsed lasers; (b) thermal damage from radiation absorption that increases the temperature of retinal tissues; (c) photochemical damage activated by absorbed photons of sufficient energy incident on the retina. The first two mechanisms require extremely high intensities not experienced with use cases for any type of light source used in architectural lighting. In the 1970s it was discovered that photochemical damage in the primate retina from the blue-light hazard can occur under specific exposure conditions [35], which might be experienced by humans from commercial light sources.
Cytotoxicity and genotoxicity of light emitted by incandescent, halogen, and LED bulbs on ARPE-19 and BEAS-2B cell lines
Published in Journal of Toxicology and Environmental Health, Part A, 2018
Marta Gea, Tiziana Schilirò, Paola Iacomussi, Raffaella Degan, Sara Bonetta, Giorgio Gilli
Optical radiation includes ultraviolet (UV) light (100–380 nm), visible light (380–780 nm), and infrared radiation (IR) (780–10, 000 nm). Visible light can be divided into blue (short-wavelength radiation), green (medium-wavelength radiation), and red light (long-wavelength radiation) (Youn et al. 2009).