Succeeded in making my first exposure today. At the moment, I am working with cyanotype paper. This is pretty cheap, 50-70 eurocent per sheet, and easy to develop with water.
The dosage was not optimized. The polygon speed was 2400 RPM. The laser driver was set at 50% of max power. Each line was exposed 10 times, so the speed of the scan head was something like 0.2 mm per second. The line speed of the scanner was 1 m/s. The laser frequency is 400.000 Hz.
Besides the not perfect dosage, there are several other issues. The laser goes through and over the prism. So lines are visible in the end result. The text in the final image is flipped,