substrate-free grid optics
Continuously Variable Attenuators
The LASNIX continuously variable attenuator precisely controls power and polarization of a transmitted CO2 laser beam. The other beam parameters such as alignment stay unaffected.
The instrument contains two rotatable grid polarizers in a compact housing. It can be used alone or directly mounted on a CO2 laser. Both grids rotate smoothly and independently. Direct, calibrated scales serve two different purposes:
(i) rotating the first grid smoothly attenuates the transmitted power down to four orders of magnitude, while keeping the polarization direction constant;
(ii) rotating the second grid sets the polarization direction of the transmitted beam at an arbitrary angle, independent of the input polarization.
The design principle is based on proprietary free-standing metal grid technology introduced by LASNIX in 1984. Since the polarizer grids are freely suspended, i.e. have no substrate, they can not offset the beam in contrast to common substrate-bound optical elements. The polarized transmitted beam passes undeviated even at the upper power limit. The mode structure and other beam properties, including the divergence and M2 parameters are fully preserved.