Ophir-Spiricon Announces Neutral Density Laser Beam Filters for UV Wavelengths

The UV ND Filters include a C-mount holder for universal application to Ophir-Spiricon's CCD and Pyroelectric cameras. Three filter holders are provided with two filters in each holder. Application is quick and easy. A holder is slid into the housing slot, and then a click is felt when the filter is properly aligned with the beam. Six filters provide an attenuation range of 0.3 to 6.0 optical densities (OD), permitting best use of the dynamic range of beam profiling cameras.

The filters include 0.3, 0.7, 1.0, 2.0, 3.0, and 4.0 OD. Two filters can be used at once for attenuation in 0.3 or 0.4 OD steps. Most ND filters that are used to attenuate laser beams are made from bulk absorbing SCHOTT glass, stated Gary Wagner, President, Ophir-Spiricon. But glass does not transmit wavelengths shorter than about 390nm. Ophir-Spiricon's UV ND Filters are made from Fused Silica with an Inconel coating on one surface to effect the attenuation of incident light. The filters are tilted to eliminate any parallel, reflecting surfaces that can cause interference effects. The UV ND Filters provide a 20mm clear aperture that will not vignette any of the compatible cameras. The damage threshold is 100W/cm2 for CW lasers and 20mJ/cm2 for nanosecond pulse wide lasers. For attenuation of high power UV lasers, the company's LBS-300 Beam Sampler contains a set of the UV ND Filters and measures power levels from 10mW to 400W.