| Popis: |
The metal and semiconductor films (MSF), deposited on the glass and metal substrates, have been used as recording materials when fabricating diffraction gratings by pulse laser irradiation of 1.06 micrometers . The processes of photothermal ablation are the basis for mechanism of diffraction structure formation. The gratings at spatial frequencies of 100 and 500 mm -1 have been fabricated without postexposure treatment by pulse laser irradiation of 20, 100 and 1000 ns in duration. It has been shown that dependence of threshold energy density E thr from pulse duration (tau) is well approximated by function E thr varies direct as(root)(tau) . The relief-phase component of the grating's diffraction efficiency (DE) has been measured. |
