Measuring Fluence Distribution Of Intense Short Laser Based On The Radiochromic Effect

This Letter demonstrates a novel, to the best of our knowledge, method to measure the fluence distribution of an intense short laser pulse based on the radiochromic effect. We discovered that an intense short laser pulse can induce the color reaction with a radiochromic film (RCF). Further, the net optical density of an irradiated RCF is proportional to the fluence of the incident laser pulse in a large range (2-120 mJ/cm(2)). This method supports a large detection area up to near square-meter scale by splicing multi-pieces of RCFs (8 x 10 inch(2) each). The spatial resolution reaches as high as 60 lines/mm. It offers a thin-film (similar to 100 mu m thick), flexible, vacuum-compatible solution to intense short laser measurements, especially to laser facilities above petawatt, with beam sizes up to near square-meter scale, e.g., extreme light infrastructure. (C) 2021 Optical Society of America