Optical reflectivity study of silicon ion implanted poly(methyl methacrylate)

The optical reflectivity (both specular and off-specular) of poly(methyl methacrylate) (PMMA) implanted with silicon ions (Si+) at energy of 50 keV, is studied in the spectral range 0.25-25 μm. The effect from the Si+ implantation on the reflectivity of two PMMA materials is examined in the dose range from 1014 to 1017 ions/cm2 and is linked to the structure formed in this ion implanted plastic. As compared to the pristine PMMA, an enhancement of the reflectivity of Si+ implanted PMMA is observed, that is attributed to the modification of the subsurface region of PMMA upon the ion implantation. The ion-produced subsurface organic interface is also probed by laser-induced thermo-lens.