An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Lee KL, Wu SH, Lee CW, Wei PK.Lee KL, et al. Among authors: wu sh.Opt Express. 2011 Nov 21;19(24):24530-9. doi: 10.1364/OE.19.024530.Opt Express. 2011.PMID: 22109480Free article.