tailieunhanh - Báo cáo hóa học: " Iridium wire grid polarizer fabricated using atomic layer deposition"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : Iridium wire grid polarizer fabricated using atomic layer deposition | Weber et al. Nanoscale Research Letters 2011 6 558 http content 6 1 558 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Iridium wire grid polarizer fabricated using atomic layer deposition 1 1 2 1 Thomas Weber Thomas Kasebier Adriana Szeghalmi Mato Knez Ernst-Bernhard Kley and Andreas Tunnermann1 3 Abstract In this work an effective multistep process toward fabrication of an iridium wire grid polarizer for UV applications involving a frequency doubling process based on ultrafast electron beam lithography and atomic layer deposition is presented. The choice of iridium as grating material is based on its good optical properties and a superior oxidation resistance. Furthermore atomic layer deposition of iridium allows a precise adjustment of the structural parameters of the grating much better than other deposition techniques like sputtering for example. At the target wavelength of 250 nm a transmission of about 45 and an extinction ratio of 87 are achieved. Keywords optics nanostructure fabrication polarizing devices 1 Introduction Wire grid polarizers offer a large spectral working range small feature size and good integrability and are of utmost importance for various applications such as microscopy or imaging systems. Generally a wire grid polarizer consists of a periodical arrangement of conductive metallic wires on a transparent substrate. Upon illumination a wire grid polarizer shows a higher transmission for light with the electrical field vector perpendicular to the wires transverse magnetic TM polarization than for the parallel counterpart transverse electric TE polarization . In addition to the transmission of TM-polarized light the extinction ratio which is defined by the ratio of TM- and TE-polarized light is another characteristic optical property of a wire grid polarizer. The spectral working range and the optical properties of a wire grid polarizer are determined by the grating material and the