Experimental investigation of correlation between surface amplitude parameters of frosted glass diffuser and size of polishing grit

Frosted glass (FG) diffusers are used for various purposes in optical experiments and are qualitatively classified based on the particle size of the grit used to polish them. Moreover, their surface topographies are known to affect their optical ability. However, a quantitative relationship between the surface topography (especially the surface amplitude parameters) and the polishing grit size is yet to be established. In the present study, a contact-type surface roughness measurement instrument was used to measure the surface amplitude parameters of a variety of commercial FG diffusers. The determined parameters, which are defined in ISO 4287-1997, were then compared with the root mean square of the grit size and the quantitative relationships were investigated. The parameters that were most strongly correlated with the root mean square of the grit size were identified. The established relationships, which statistically reflect the optical properties of an FG diffuser, may be used to optimally select a diffuser for a particular optical experiment or numerical calculation.