<title>Fabrication of phase gratings in glass by ion implantation</title>

Abstract

Transmission phase gratings of grating constants of 4, 6, 8 and 12 micrometers have been designed and fabricated in glass samples via implantation of helium and nitrogen ions of energies in the 500 keV - 1.6 MeV range, through photoresist masks of thickness of 3.3 micrometers . Both mono- and multienergy implantations have been applied. The gratings have been studied by measuring the diffraction efficiencies. The phase profiles of the lines of the gratings have also been measured directly via interference and phase contrast microscopy and scanning electron microscopy. It was found that the profile of the implanted gratings differed significantly from the quasi rectangular profile of the mask, especially in case of the two finest gratings. The highest first order diffraction efficiencies were around 20%. The dependence of the efficiencies of the gratings on the energy and dose of the implantation have been measured.