Fabrication of micro-optical structures by applying negative tone hybrid glass materials and greyscale lithography

Author

Kärkkäinen, A. H O ; Rantala, J.T. ; Descour, M.R.

Author_Institution

VTT Electron., Oulu, Finland

Volume

38

Issue

1

fYear

2002

fDate

1/3/2002 12:00:00 AM

Firstpage

23

Lastpage

24

Abstract

Direct lithographic patterning of lenslet arrays with lens sags up to 75 μm and opto-mechanical structures with thickness up to 118 μm is demonstrated. using negative tone hybrid glass materials and greyscale and binary photomasks. The hybrid glass material features a maximum extinction coefficient of 2.0 × 10^-4 μm^-1 between 450 and 1600 nm, a refractive index of 1.531 at 632.8 nm and an estimated Abbe number of 45. The patterned structures exhibit rms surface roughness between 10 to 45 nm

Keywords

masks; micro-optics; microlenses; optical fabrication; optical glass; photolithography; refractive index; surface topography; 10 to 45 nm; 118 micron; 450 to 1600 nm; 632.8 nm; 75 micron; binary photomasks; direct lithographic patterning; estimated Abbe number; greyscale lithography; lens sags; lenslet arrays; maximum extinction coefficient; micro-optical structure fabrication; negative tone hybrid glass materials; opto-mechanical structures; patterned structures; refractive index; rms surface roughness; thickness;

fLanguage

English

Journal_Title

Electronics Letters

Publisher

iet

ISSN

0013-5194

Type

jour

DOI

10.1049/el:20020032

Filename

977537