Minnesota Mining and Manufacturing Company

Kent N Maffitt

Richard F Willson

William B Robbins

Dean R Lowrey

Hubert U Brueckner

An optical recording medium containing a light-absorbing film of a refractary material selected from the group, consisting of boron, borides of carbon, silicon, hafnium, niobium, tantalum, titanium, tugsten, and zirconium, nitrides of boron, hafnium, tantalum and titanium, oxides of hafnium, cerium, magnesium and thorium, and silicides of niobium, tantalum, titanium, and tungsten less than 60 nm thick and which is sufficiently plastic to allow deformation upon localized heating by exposure to a focused laser beam, whereupon the localized heating of the light absorbing film enables information storage in the form of localized protuberances in the heated areas which can be used as a master for replication purposes.

Protuberant optical recording medium

An optical recording medium containing a light-absorbing film of amorphous carbon less than 60 nm thick and which is sufficiently plastic to allow plastic information upon localized heating is provided for exposure to a focused laser beam, whereupon localized heating of the light-absorbing film enables information storage in the form of localized protuberances in the heated areas which can subsequently be optically detected and can be used as a master information record for replication purposes.

A method is disclosed for producing a micro structure on the surface of an article. The method comprises the steps of depositing a discontinuous coating of a material exhibiting a low rate of sputter etching on a substrate exhibiting a higher rate of sputter etching and differentially sputter etching the composite surface to produce a topography of pyramid-like micropedestals random in height and separation. The articles produced by this method are characterized by both the microstructured surface and by the detectable presence of the material exhibiting the lower rate of sputter etching. The microstructured surface results in the articles having uniform antireflecting properties over a large range of angles of incident light and over an extremely broad range of wavelengths, in which the antireflecting characteristic is obtained without an attendant increase in diffuse scattering. Also, the microstructured surface results in the articles being characterized by a high degree of adherence, such that the treated surface may be considered to be 'primed', thereby enabling the application of highly adherent coatings or layers thereon.

Method of producing a microstructured surface and the article produced

An optical element of polymeric material is provided with a microstructured surface, thereby rendering the surface substantially non-reflecting while maintaining a high degree of transmissivity. The element is formed via replication from a stamper prepared from a glass original having a similar microstructured surface which is formed by etching a cleaned surface of the glass in vapors of hydrofluoric acid followed by sputter etching with inert gas ions.

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Minneapolis, MN, United States of America

Kent N Maffitt