An official website of the United States government
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.
Ulf Griesmann (Fed)
Ulf Griesmann is a physicist in the Surface and Interface Metrology Group in the Sensor Science Division of the Physical Measurement Laboratory (PML) at the National Institute of Standards and Technology (NIST).