PHOTODEPOSITION OF DIFFRACTION GRATINGS IN GLASS

Line patterns with spacings ranging from 10 to 50 mu m have been achie ved by 488 mm photolysis of porous glasses impregnated with Fe(CO)(5). Photolysis was accomplished with a focused Ar+ laser impinging onto a sample mounted on a computer-controlled X-Y stage programmed to creat e a line pattern. The photodeposited grating was tested by generating a diffraction pattern with a He-Ne laser, which was then used to calcu late the grating line spacings. The measured line spacings were found to be in excellent agreement with the spacings defined by the computer -driven stage. Consolidation of the porous glass occurs at 1200 degree s C, and decreases the sample volume as much as 35%. Line spacing decr eases in direct proportion to the decrease in the dimension perpendicu lar to the grating Lines of the sample and consolidation yields gratin gs that are capable of diffracting light, stable under a variety of co nditions, and unaffected by high laser powers.