High-performance large-area ultra-broadband (UV to IR) nanowire-grid polarizers and polarizing beam-splitters

Abstract

Aluminum nanowire-grid polarizers and polarizing beam splitters with a fixed pitch (i.e., period) of ~146 nm but a wide range of linewidths (from < 60 nm to 90 nm) and heights (from 150 nm to 200 nm) are studied. Immersion interference lithography, UV-nanoimprint lithography and aluminum reactive ion etching were used to fabricate the nanowire-grid polarizers. Optical performance of the nanowire-grid polarizers was characterized in a broad spectral range from UV (< 400 nm) to near infrared (> 1700 nm). The performance trade-off between transmittance/reflectance and extinction ratio is investigated in details. The developed highperformance large-area broadband nanowire-grid polarizer opens the potential for many optical applications particularly integrated optics.

Integrated nano-optic devices based on immersion nano-gratings made by imprint lithography and nano-trench-filling technology

“…To do so, a mold was fabricated first. We used deep-UV interference lithography to make a 148 nm-period mold on a 100 mm in-diameter glass wafer [33][34][35]. For making the nanowire-grid polarizer, we started with a 100 mm in-diameter BK7 wafer coated on one side with a 130 nm thick aluminum film by a high vacuum evaporation.…”

“…Then a thin layer (~180 nm) of UV curable low-viscosity resist layer was spin-coated on [7]. A UV nano-imprint process was used to pattern the resist with the previously made mold [35]. After imprint and O 2 polymer truncate [7], a chlorine-based reactive ion etching (RIE) with 60 sccm BCl 3 and 50 sccm Cl 2 at 5 mtorr was then used to etch aluminum into nanogratings.…”

A bio-inspired model for bidirectional polarisation detection

“…The extinction ratio reached 103, but the transmittance was less than 60%. Wang et al [19] developed a polariser with a transverse magnetic (TM) transmittance greater than 90%; however, in the visible regime, the TE transmittance rose to ~10%, and the extinction ratio was less than 10. Thus, despite these achievements, it has been difficult to achieve high TM transmittance and high extinction ratios simultaneously with integrated polarisation detection.…”