title: Generating a sub-wavelength Bessel-like light beam using a tapered hollow tube.
abstract: We present a series of sub-wavelength annular aperture (SAA) structures with annular width equal to the tip of a tapered hollow tube, which was fabricated using a heat-pulled method. The light beams emitted from the SAA-like structures created by the tapered hollow tube produced light beams characteristic of Bessel beams. We obtained a sub-micrometer focal spot with a depth-of-focus larger than 7 μm and identified the proper structure parameters needed to generate Bessel-like light beams. Our new design has potential application to areas such as optical lithography, optical trapping, and the fabrication of high aspect ratio structures.
authors.affiliation: Institute of Applied Mechanics, National Taiwan University, Taipei, Taiwan.
authors.forename: Chun-Yen
authors.initials: CY
authors.lastname: Chen
authors.forename: Yu-Hsun
authors.initials: YH
authors.lastname: Lee
authors.forename: Chih-Jen
authors.initials: CJ
authors.lastname: Chien
authors.forename: Ming-Han
authors.initials: MH
authors.lastname: Chung
authors.forename: Yuh-Yan
authors.initials: YY
authors.lastname: Yu
authors.forename: Te-Hsun
authors.initials: TH
authors.lastname: Chen
authors.forename: Chih-Kung
authors.initials: CK
authors.lastname: Lee