More expensive is silver, which has a reflectivity of 95%-99% even into the far infrared, but suffers from decreasing reflectivity (<90%) in the blue and ultraviolet spectral regions. Metals are known for having high reflectivity, which explains their shiny appearance. B 9, 5056-5070 (1974) Data [ CSV - comma separated ] [ TXT - tab separated ] [ Full database record ] The simplest optical coatings are thin layers of metals, such as aluminium, which are deposited on glass substrates to make mirror surfaces, a process known as silvering. Rev. It is as if the light is generated from the metal itself. Protected Silver provides the highest reflectance between 500 – 800nm and also performs well in … With metals, it is often desired to have a reflective surface-not necessarily blindingly bright but one that catches the eye. UV and DUV Enhanced Aluminum can be used for UV and visible applications. Its relative reflectivity is much greater than surrounding surfaces. Spectrum Thin Films can design metallic coatings for optical mirrors – laser, flat, metal substrate, focusing, or specialty mirrors in a range of reflective coating options at different regions of the spectrum, including aluminum, silver, gold, or dielectric. A gold leaf surface shimmers in the sunlight like a beacon when seen from a distance. Bare or Protected Gold offers high reflectance for near­Infrared (NIR) and Infrared wavelengths. lesser number of photons get inelastically scattered, these heat up the metal. Transition metals such as Fe, Ni, Pd, and Pt that have low optical reflectivity do … Since the reflectance of light by metals is high, their absorption must also be high, because a high reflectance implies that light cannot penetrate the metal with considerable efficiency. Most expensive is gold, which gives excellent (98%-99%) reflectivity throughout the infrared, but limited reflectivity at wavelengths shorter than 550 nm, resulting in the typical gold colour. The metal used determines the reflection characteristics of the mirror; aluminium is the cheapest and most common coating, and yields a reflectivity of around 88%-92% over the visible spectrum. So metals are highly reflective, because: most of the photons get elastically scattered, that is reflection. very little number of photons get absorbed in the visible range, most of … The SERS signal can be enhanced by a factor proportional to the fourth power of the enhancement of the local incident near field with metals that have high optical reflectivity such as silver, gold, and copper. Optical constants of transition metals: Ti, V, Cr, Mn, Fe, Co, Ni, and Pd, Phys. Given that reflectance is a directional property, most surfaces can be divided into those that give specular reflection and those that give diffuse reflection.