U.S. flag

An official website of the United States government

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.

Physical Measurement Laboratory

Developing and delivering trusted measurements to support national needs.

diagram of a spherical retarding field analyzer
NIST Study Aims to Improve Utility of the Scanning Electron Microscope
When an ordinary beam of neutrons strikes the team’s silicon grating, the millions of scored lines on the grating convert the neutrons into an Airy beam, whose wavefront travels along a parabolic path. The triangular shapes on the detector match the predicted behavior of an Airy beam, offering evidence of the team’s success.
NIST’s Curved Neutron Beams Could Deliver Benefits Straight to Industry

News and Updates

World Metrology Day Symposium 2025

BIPM 150th Anniversary Standout Poster

The Office of Weights and Measures (OWM) invites you to celebrate World Metrology Day (20 May 2025) marking the sesquicentennial, or 150th anniversary, of the
fraudulent five-gallon measure

Deception, Trickery, and Metrology

While exploring a box of early 20th century index cards in the NIST archives, I stumbled upon two that starkly illustrated one of NIST's missions – legal

Events

Awards

View All Awards

Press Coverage

When an ordinary beam of neutrons strikes the team’s silicon grating, the millions of scored lines on the grating convert the neutrons into an Airy beam, whose wavefront travels along a parabolic path. The triangular shapes on the detector match the predicted behavior of an Airy beam, offering evidence of the team’s success.

Neutron Airy beams make their debut

Physics World
Physicists have succeeded in making neutrons travel in a curved parabolic waveform known as an Airy beam. This behaviour, which had previously been observed in

Patents

Continuous-Wave Laser Source And Making A Continuous-Wave Laser Source

NIST Inventors
Scott Papp
A method of designing a continuous-wave laser source having a target output wavelength and an input laser with a wavelength different from the target output wavelength includes the steps of receiving the target output wavelength, and subordinate properties of the laser source; determining a

Sound Pressure Metrology Instrument And Determining Sound Pressure From Index Of Refraction

NIST Inventors
Richard A. Allen , Randall P Wagner , Benjamin Reschovsky and Akobuije Chijioke
A sound pressure metrology instrument determines sound pressure from index of refraction and includes: a light source that produces source light; the optical cavity that: receives an acoustic field from the sound source; receives the source light from the light source; produces acoustic-modified

Contacts

PML Director and Deputy Director

Associate Director for Measurement Services and Associate Director