Skip navigationShow sitemap

Glossary VITRON – Your Material Specialist

A - MAR coating

In order to increase translucency optical functional surfaces are coated with layers consisting of materials with adapted refractive indexes which reduce reflection. The higher the medium's refractive index, the more necessary an antireflexion coating to increase light transmisson. There are narrowband and broadband antireflexion coatings. Using multiple layers a translucency of over 99% can be realized in selected wavelength ranges even for materials with high refractive indexes.

CVD zinc sulfide

CVD zinc sulphide is produced in a CVD-process with zinc vapour and hydrogen sulphide. The polycristalline material consists mainly of the cubic sphalerite. Even small amounts of the hexagonal modification wurtzite and other defects lead to a strong light dispersion in the visible and near infrared area. This is why the yellow material, which is opaque in the visible area, is only used in the middle infrared area (7,5 to 11 �m). Is is often referred to as "as grown" or FLIR-material. The FLIR-material can be transferred into the colourless, multispectral zinc sulphide, which is transparent in the visible area as well, using hot isostatic pressing.

Chalcogenide glasses

Chalcogenide glasses are amorphous solids in which the glass-forming elements (silicon and oxygen in "normal" glass) are contained in the form of germanium, arsenic und the heavy chalcogens sulphur, selenium and tellurium. Due to the heavier elements and the weaker chemical bond translucency shifts from the visible into the infared spectral range. Chalcogenide glasses are semiconductors. Their mechanical rigidity and thermal resistance are smaller than those of glasses for the visible spectral range, but their thermal expansion is considerably stronger.

hot isostatic pressing (HIP)

HIP means hot isostratic pressing, a process which is used for quality improvement of powder metallic products or founding parts. In the process the parts are redensified in special autoclaves at high temperatures and through the high, all side pressure of an inert gas. The pressure can be up to 200MPa and the temperature up to 1400�C. CVD-zinc sulphide can be transferred from the opaque FLIR-quality into the multispectral form by means of an HIP-Process.

IR materials

IR-materials are needed in the production of optical components (lenses, windows, prisms etc.) used in the infrared spectral range. All these materials are transparent for infrared radiation. Apart from that, this group of materials is characterized by a great variety: ionic mono-crystals (such as sodium chloride), semiconductors in a monocrystalline or polycrystalline form (such as germanium or silicon), polycrystalline II-VI-compounds (such as zinc sulfide or zinc selenide) or chalcogenide glasses, to name just a few.

machinable glass ceramic

Glass ceramic is a material which is made from a glass through controlled crystallisation. In the process, the types of crystals determine the desired characteristics of the glass ceramic. The machinable glass ceramic VITRONIT contains 60% of a mica phase in a glassy matrix. Due to the good fissility of the mica crystals VITRONIT can be machined with carbide tools. It is especially suitable for the production of high-precision ceramic components. No firing is required.

O - Toptical components

Optical components are unmounted lenses, prisms, windows etc.

optischen Komponenten

Optische Komponenten sind ungefasste Linsen, Prismen, Fenster u.s.w.

Refractive index

The refractive index, also called index of refraction, is an important measure in geometrical optics. It indicates the extent to which a light beam is refracted and reflected when passing from one medium to another. It is defined as the ratio of the speed of light in a vacuum to the speed of light in the respective medium. The refractive index is independent of wavelength, thus the spectral analysis of light is possible.

Transmission

Transmission means the light transfer of an optical material. The part of the luminous flux which completely permeates a transparent component is called the degree of light transmission. It is a function of the chemical and physical structure and varies according to the wavelength. The intensity of the incident light is reduced by reflexion on both surfaces and by absorption within the material. The transmission range is the range of the electromagnetic spectrum in which the absorption is much higher than the transmission.

Thermographic cameras

Thermographic cameras are imaging devices similar to a photographic camera. The difference lies in the spectral range employed. Thermographic cameras usually work within the range between 1 and 2�m. The imaging optic therefore needs to be transparent for these wavelengths. The thermographic image is projected on cooled or uncooled detectors and visualized. Thermographic cameras are used as night vision devices in the security and military areas. In recent years, the use in engineering and automotives has greatly increased.

Do you have any questions?We'll answer them.

Send us your request now!
We will get back to you as soon as possible.
Also, feel free to call us at the following number: +49 (0) 36 41 288 130.

+49 (0) 36 41 288 130
Zum Seitenanfang