Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2016 Apr 6;6:23494. doi: 10.1038/srep23494

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

Copyright © 2016, Macmillan Publishers Limited

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareALike 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/4.0/

PMC Copyright notice

(a) Images of focal spot at different focal distances. Each image is normalized with respect to peak intensity. (b) Theoretical and experimental full width at half maximum (FWHM) of the focal spot at different focal distances.