BS ISO 19986:2020 pdf free.Lasers and laser-related equipment一Test method for angle resolved scattering.
BS ISO 19986 This document describes procedures for the determination of the angle resolved scattering by optical components such as coated or uncoated optical elements, photonic structures, and materials that can be transparent, translucent, or opaque. It comprises scattering into the scattering sphere around the specimen usually separated into the backward and forward hemispheres. The procedures apply to wavelengths of radiation ranging from 5 nm in the extreme ultraviolet to 15 μm in the infrared spectral ranges.The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 11145, Optics and photonics – – Lasers and laser-related equipment一Vocabulary and symbols ISO 14644-1, Cleanrooms and associated controlled environments一Part 1: Classification of air cleanliness by particle concentrationThe fundamental operating principle of the instrument for ARS measurements (see Figure 2) is based on measuring the radiant power scattered from the specimen as a function of the scattering angles using a detector with a small but finite aperture that is scanned along a defined trajectory on or within the full scattering sphere about the specimen. The simplest type of measurement is a detector scan with the plane of incidence (in-plane scan).The angle of incidence is kept constant during a single measurement. The ARS is either measured by rotating the detector with respect to the specimen and the ilumination system, or, alternatively, the detector is fixed and the illumination system and the specimen are rotated with respect to the detector.The instrument should be located in a clean room environment or under a laminar flow system to prevent scattering from dust particles. Some applications, in particular in the UV range, require operation in vacuum or specific gas atmospheres to avoid absorption of radiation in air or to suppress Rayleigh scattering from air molecules. The environmental conditions during measurements shall be documented.BS ISO 19986 pdf download.