Fabrication of Multilevel Silicon Diffractive Lens at Terahertz Frequency

Author

Saha, S.C. ; Li, Cong ; Ma, Yanru ; Grant, J.P. ; Cumming, D.

Author_Institution

Electron. & Nanoscale Eng. Dept., Univ. of Glasgow, Glasgow, UK

Volume

3

Issue

4

fYear

2013

fDate

Jul-13

Firstpage

479

Lastpage

485

Abstract

In this paper, we fabricated an anisotropically etched multilevel silicon diffractive lens. The operating frequency and focal length of the lens are 2.52 THz and 15 mm, respectively. Both 4- and 16-level lenses have been realized. The total etch depth and size of the lenses are 49 μm and 45 mm × 45 mm. Positive tone thick resist AZ 4562 was used as a mask material for dry etching the high resistivity silicon substrate. We have characterized the lens using a high power continuous wave far infrared laser operating at 2.52 THz. The measured results show good agreement with the designed specifications.

Keywords

etching; infrared spectra; lenses; masks; micro-optics; optical fabrication; photoresists; silicon; submillimetre wave lasers; anisotropically etching; depth 49 mum; dry etching; focal length; frequency 2.52 THz; high power continuous wave far infrared laser; mask material; multilevel silicon diffractive lens; positive tone thick resist AZ 4562; size 45 mm; total etch depth; Beam steering; lenses; microoptics; optical device fabrication; silicon devices; submillimeter-wave devices;

fLanguage

English

Journal_Title

Terahertz Science and Technology, IEEE Transactions on

Publisher

ieee

ISSN

2156-342X

Type

jour

DOI

10.1109/TTHZ.2013.2251929

Filename

6487429