Design of antireflective subwavelength grating structure for infrared medical imaging

Author

Zheng, Xun ; Je, Soonkyu ; Kim, Byungwook ; Shim, Jongmyeong ; Kang, Shinill

Author_Institution

Nano Fabrication & Micro Opt. Nat. Res. Lab., Yonsei Univ., Seoul, South Korea

fYear

2010

Firstpage

767

Lastpage

768

Abstract

A subwavelength grating (SWG) structure was designed and simulated on a germanium substrate to reduce the Fresnel reflection of transmissive optical elements. Three different grating structures were compared and analyzed by solving Maxwell´s equations using rigorous coupled wave analysis (RCWA) method. The designed antireflective SWG of 2 dimensional sinusoidal structure has pitch of 2.3 Â¿m and pattern height of 3.3 Â¿m for maximum sensitivity of infrared medical camera at wavelength ranging from 8 Â¿m to 12 Â¿m. The 2D photoresist sinusoidal grating structure, to be used as etching barrier for fabrication of antireflective germanium grating structure, was fabricated by laser interference lithography.

Keywords

Fresnel diffraction; biomedical imaging; diffraction gratings; germanium; infrared imaging; 2D photoresist; Fresnel reflection; Ge; Maxwell´s equations; antireflective germanium grating structure; antireflective subwavelength grating structure; etching barrier; infrared medical imaging; laser interference lithography; rigorous coupled wave analysis; sinusoidal grating structure; transmissive optical elements; wavelength 8 mum to 12 mum; Biomedical imaging; Biomedical optical imaging; Fresnel reflection; Germanium; Gratings; Infrared imaging; Medical simulation; Optical design; Optical sensors; Reluctance generators;

fLanguage

English

Publisher

ieee

Conference_Titel

Nanoelectronics Conference (INEC), 2010 3rd International

Conference_Location

Hong Kong

Print_ISBN

978-1-4244-3543-2

Electronic_ISBN

978-1-4244-3544-9

Type

conf

DOI

10.1109/INEC.2010.5424458

Filename

5424458