[OPTICAL REVIEW Vol. 9, No. 5 (2002) 183-185]

Broadband Antireflection Subwavelength Gratings for Polymethyl Methacrylate Fabricated with Molding Technique

Yoshiaki KANAMORI and Kazuhiro HANE

Department of Mechatronics and Precision Engineering, Tohoku University, Aoba-01, Aramaki, Aoba-ku, Sendai 980-8579, Japan

(Received March 16, 2002; Accepted July 16, 2002)

We fabricated a two-dimensional subwavelength grating (SWG) on a polymethyl methacrylate (PMMA) film using a molding technique. A method of fabricating SWGs with high accuracy using a replica technique in an atmospheric environment was proposed. The SWG consisted of tapered gratings with a 200 nm period and a 200 nm deep groove. The reflectivity at wavelengths from 400 nm to 800 nm was measured and compared with the results calculated on the basis of rigorous coupled-wave analysis. At these wavelengths, the reflectivity decreased to approximately half that of the PMMA film.

Key words: subwavelength grating, antireflection, mold, polymethyl methacrylate, micromachining, rigorous coupled-wave analysis