Fabrication of free-standing lithium niobate nanowaveguides down to 50 nm in width. (18th December 2015)

• Record Type: Journal Article
• Authors: Geiss, Reinhard; Sergeyev, Anton; Hartung, Holger; Solntsev, Alexander S; Sukhorukov, Andrey A; Grange, Rachel; Schrempel, Frank; Kley, Ernst-Bernhard; Tünnermann, Andreas; Pertsch, Thomas
• Is Part Of: Nanotechnology. Volume 27:Number 6(2016)
• Publication Date: 2015-12-18
• Subjects: nanoscale waveguide -- lithium niobate -- second-harmonic generation -- ion-beam enhanced etching -- electron-beam lithography; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/0957-4484/27/6/065301
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: Nonlinear optical nanoscale waveguides are a compact and powerful platform for efficient wavelength conversion. The free-standing waveguide geometry opens a range of applications in microscopy for local delivery of light, where in situ wavelength conversion helps to overcome various wavelength-dependent issues, such as biological tissue damage. In this paper, we present an original patterning method for high-precision fabrication of free-standing nanoscale waveguides based on lithium niobate, a material with a strong second-order nonlinearity and a broad transparency window covering the visible and mid-infrared wavelength ranges. The fabrication process combines electron-beam lithography with ion-beam enhanced etching and produces nanowaveguides with lengths from 5 to 50 μ m, widths from 50 to 1000 nm and heights from 50 to 500 nm, each with a precision of few nanometers. The fabricated nanowaveguides are tested in an optical characterization experiment showing efficient second-harmonic generation.