A new Laser Attenuator has been developed, which utilises an ultra-hard coated, Laser Optical Multilayer Attenuator (LOMA) filter from Delta Optical Thin Film.
The laser attenuator enables computer-controlled attenuation of a monochromatic light source from 1 to 99 per cent within the wavelength region of ~ 550-1,000 nm. It provides the user with safe, repeatable, and real-time control over the attenuation by combining the LOMA filter with a linear drive, controlled electronics, and dedicated software.
This filter is based on an optical thin film coating that works on reflection, unlike other filters that work on absorption. This feature allows the LOMA filters to withstand high laser power as it attenuates the laser with no absorption of the input power.
The laser beam is transmitted without distortion of the beam profile, and no extra optics are required. No pulse broadening is observed, even with short laser pulses down to 70fs. The optical coating works independently of polarisation, and it is designed for a wide range of laser wavelengths between 550 and 1,000nm.