For lasers with infrared wavelengths, such as, for example, 10.6 µm in CO2 lasers, lenses and windows made of zinc selenide (ZnSe) are used. Silicon or copper mirrors are used as mirrors. Phase shift mirrors used to produce circular polarization are also available. Beam expanders and diffractive elements for beam shapes complete our product range.
Only high-quality substrates are used for the optics. Different lens shapes are available.
Zinc selenide components are primarily used for transmissive optics. They are made exclusively with high quality "laser grade" material that can be used even in the kW range. When coated, these zinc selenide elements have a transmittance of T > 99.4 % at 10.6 µm.
Meniscus lenses are generally used as cutting lenses. They have a convex/concave surface by which the relevant aberration – the spherical aberration – is reduced. The achievable focus diameter is smaller than that of plano-convex/plano-concave lenses, particularly at short focal lengths. Because the lenses typically serve as the endpoint of the excess pressure region in a cutting head, the required edge thickness and the resulting maximum pressure load must be increased as necessary. For this reason, we differentiate between normal pressure and high pressure lenses.
Because of their lens shape, plano-convex/plano-concave lenses are easy to produce. Together a planar and a curved surface produce the required refractive power of a lens.
In many applications, in particular at long focal lengths, these lenses can be used without a problem. However, the shorter the focal length or the larger the beam diameter, the greater the spherical aberration. Then meniscus lenses are preferred.
Biconvex/biconcave lenses have two equally curved surfaces and are used in rare cases at short focal lengths.
These lenses are only available custom made.
Cylindrical lenses have a planar and a curved surface in which the radius continues along an axis, which results in a focal line instead of a focal point.
Specifications are available upon request.
Due to the infrared wavelength of 10.6 µm, only a few materials are suitable for use with CO2 lasers. In addition to the transmission properties, the optical and thermal properties of the material must also be taken into account.
Zinc selenide (ZnSe) has been established as the standard material for lenses and windows.
Germanium and gallium arsenide components are also available upon request.