Nonlinear microscopy using cylindrical vector beams: Applications to three-dimensional imaging of nanostructures.

Godofredo Bautista,Martti Kauranen,Lasse Karvonen,Joona-Pekko Kakko,Esko Kauppinen,Xiaorun Zang,Hua Jiang,Harri Lipsanen,Veer Dhaka

doi:10.1364/oe.25.012463

Abstract

The three-dimensional (3D) optical fields that arise from the focusing of cylindrical vector beams (CVB) with radial and azimuthal polarizations provide new sources of contrast for optical microscopy of nano-objects. So far, these demonstrations have been restricted to two-dimensional transversal scanning, i.e., along the focal plane of interest, or use of point-like objects, i.e., single molecules and nanoparticles. Here, we demonstrate the first application of CVBs for 3D imaging of 3D nano-objects. This technique is done by acquiring 3D image scans of the second-harmonic generation signal from vertically-aligned semiconductor nanowires, whose second-order response is primarily driven by the longitudinal electric field, i.e., the field component along the nanowire axis. Our technique provides a new way to study individual nano-objects in three dimensions through the unique combination of nonlinear microscopy and CVBs.

Highlights

Cylindrical vector beams (CVB), e.g., radially- and azimuthally-polarized beams, and their applications in optical microscopy are subjects of growing interest [1,2,3]
The three-dimensional (3D) optical fields that arise from the focusing of cylindrical vector beams (CVB) with radial and azimuthal polarizations provide new sources of contrast for optical microscopy of nano-objects
These demonstrations have been restricted to two-dimensional transversal scanning, i.e., along the focal plane of interest, or use of point-like objects, i.e., single molecules and nanoparticles

Summary

Introduction

Cylindrical vector beams (CVB), e.g., radially- and azimuthally-polarized beams, and their applications in optical microscopy are subjects of growing interest [1,2,3]. This is mainly due to the unique properties of CVBs when strongly focused by a microscope objective [4,5,6,7,8]. The focusing of a radially-polarized beam creates a unique three-dimensional (3D) focal-field distribution that exhibits radially-polarized transversal electric components at the focal plane and non-negligible longitudinal components along the axis of beam propagation. We demonstrate the first use of CVBs for 3D nonlinear imaging of 3D nanostructures

Methods

Results

Conclusion