The effect of the duration of ultrashort laser pulses with a wavelength of 1030 nm on the process of their nonlinear absorption in polymethylmethacrylate is studied. It is found that the dependence of absorption on pulse duration is nonlinear, with an increase in the range from 250 to 450 fs, a decrease from 450 to 1500 fs, and insignificant changes after 1500 fs.
Gulina et al. (Mon,) studied this question.