Product Code: JLA_17_3_191

Authors:
A. Schirmacher
E. Sutter
O. Werhahn
U. Siegner
A. Nevejina-Sturhan
Physikalisch-Technische Bundesanstalt, Braunschweig, Bundesallee 100, 38116 Braunschweig, Germany

Induced transmittance is observed with polycarbonate laser filters when they are irradiated by laser pulses with a width of 200 fs. These results are compared with measurements in the nanosecond time domain. Calculations by a simple absorption model show, that single photon absorption is dominating the light-matter interaction at the pulse widths used in this study, at least at radiant exposure levels at which the filter material is not damaged. The use of eyewear showing induced transmittance can lead to a risk for the user, if the filter is irradiated by a strong laser beam in an accident. This situation can be even worse when an additional temperature effect is taken into account, which shifts the transmittance characteristics to lower optical densities when the temperature of the laser filter is maintained at a lower level. An example for this effect is given for nanosecond-pulse laser interactions.