Ultrahigh 22 nm resolution coherent diffractive imaging using a desktop 13 nm high harmonic source

Matthew D Seaberg,Yanwei Liu,Henry C Kapteyn,Jianwei Miao,Chien-Chun Chen,Daisy A Raymondson,Ethan L Townsend,Lu Rong,Carmen S Menoni,William F Schlotter,Daniel E Adams,Margaret M Murnane

doi:10.1364/oe.19.022470

Abstract

New diffractive imaging techniques using coherent x-ray beams have made possible nanometer-scale resolution imaging by replacing the optics in a microscope with an iterative phase retrieval algorithm. However, to date very high resolution imaging (< 40 nm) was limited to large-scale synchrotron facilities. Here, we present a significant advance in image resolution and capabilities for desktop soft x-ray microscopes that will enable widespread applications in nanoscience and nanotechnology. Using 13 nm high harmonic beams, we demonstrate a record 22 nm spatial resolution for any tabletop x-ray microscope. Finally, we show that unique information about the sample can be obtained by extracting 3-D information at very high numerical apertures.

Highlights

The quest to understand structure, dynamics and function at the nanoscale continues to drive new ultrahigh-resolution imaging technologies
An increased high harmonic flux at 13 nm was critical to our experiments, in order to significantly enhance the spatial resolution with much reduced exposure times
The data for object J407 (Fig. 2(e)–2(h)) were obtained with the CCD placed 3.6 cm past the object, corresponding to a numerical apertures (NA) of ~0.36. This allows for a maximum half-pitch resolution using coherent illumination of Δrhp = 0.5 λ/NA 18nm, calculated using the Rayleigh criterion for coherent illumination

Summary

Introduction

The quest to understand structure, dynamics and function at the nanoscale continues to drive new ultrahigh-resolution imaging technologies. Super-resolution optical imaging techniques such as multiphoton microscopy [1], stimulated emission depletion microscopy (STED) [2,3], photo-activated localization microscopy (PALM) and stochastic optical reconstruction microscopy (STORM) [4,5] have made impressive progress using visible light for super-resolution imaging. These techniques rely on scanning or on sparsely emitting labeled samples, where the centroid of single fluorescent molecules in the sample can be located down to 10 nm precision. Powerful and widely-used label-free techniques such as multiphoton [6] or CARS microscopy [7] avoid these issues, but require scanning and yield only modestly-higher spatial resolution than conventional techniques such as confocal microscopy

Methods

Results

Conclusion