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Metrology

Optical / photometry / laser metrology

Projects/Programs

Displaying 1 - 25 of 75

Absolute cryogenic infrared radiometry at the LBIR facility

Ongoing
The Strategic Defense Initiative (SDI), and subsequently the Ballistic Missile Defense Organization (BMDO) and the Missile Defense Agency (MDA) of the U.S. Department of Defense (DoD), have motivated NIST's work developing calibration methods and standards for space-based sensors used in missile
The NIST wind tunnel

Air Speed Metrology

Ongoing
NIST's wind tunnel has two interchangeable test sections. (See Fig. 1) The upper test section has a uniform cross section; the lower test section has a contracted zone in its center to achieve higher velocities. Upper test section: 2.1 m high × 1.5 m wide × 12 m long; speeds to: 45 m/s (100 mi/hour)
Aperture measurement with AMM

Aperture area measurements

Ongoing
Aperture area measurements are performed at NIST’s aperture area measurement facility, which combines a precise interferometric motion stage with high-resolution optical microscopy. This non-contact method is especially well suited for the measurement of defining apertures with knife edges that are
3D plot

Applied spectroradiometry and imaging metrology

Ongoing
Stray light correction Array instruments are subject to measurement errors arising from detector's blooming, smearing, nonlinearity, and instrument's stray light. These errors (except the stray-light error) can either be avoided or corrected in many cases. However, the stray light, due to scattered
BIB-trap detector

BIB-trap detector

Ongoing
Limitations of Standard BIB Detectors Currently available BIB detectors exhibit excellent detectivity, but are limited in their use for spectral calibrations by detection inefficiency and spectral response inhomogeneity. The maximum quantum efficiency of these doped silicon devices is near 60%
absolute cryogenic radiometer

Bilateral Comparison of Spectral Responsivity in the Vacuum-Ultraviolet

Completed
The last decade has seen numerous key comparisons in the field of photometry and radiometry between different national metrology institutes (NMIs) in the context of the Mutual Recognition Arrangement. At first, these comparisons were restricted to wavelengths longer than 200 nm, with just the

Calibration of Space Weather Observational Instruments at NIST

Ongoing
Space-weather events are naturally occurring phenomena caused by activity on the Sun that affect us here on Earth. Solar storms can impact technology we rely on daily, like e.g. the Global Positioning System (GPS), communication satellites, and electric power grids. Various phenomena that originate
Illustration of satellite sensing of sunlight reflected by buildings, roads, water and trees to assess radiative warming of the earth.

Climate Science

Ongoing
This program encompasses multifaceted efforts to advance the metrology of climate science. Projects include: development of ultra-high accuracy optical standards and technologies to determine greenhouse gases (GHGs) concentrations, atmospheric lifetimes, and aerosol radiative forcing development of

CODATA values of the fundamental physical constants

Ongoing
CODATA recommended values of the constants Database of references for data on the constants Publications: Reviews of Modern Physics ( 1998) ( 2002) ( 2006) ( 2010) ( 2014) Journal of Physical and Chemical Reference Data ( 1998) ( 2006) ( 2010) Resource Letter FC-1: The physics of fundamental
background molecule

Cold Core Technology Platform

Ongoing
Cold atoms can be useful sensors for a host of different phenomena including inertial forces like acceleration and rotation, gravity, magnetic fields, vacuum and time. However, most of these applications are still confined to the laboratory. Building robust, field-deployable quantum sensors made
EUV optics degradation in space

Degradation of extreme-ultraviolet optics

Ongoing
The primary degradation process in EUVL tools and satellite instruments begins by the adsorption of water or carbonaceous molecules from the vacuum environment onto the optic surface. The optic is damaged if the molecule undergoes photon-stimulated decomposition before it can (reversibly) thermally

Detector metrology

Ongoing
Improved detector technology in the past two decades has opened a new era in detector metrology of optical radiation measurements. Lower calibration and measurement uncertainties can be achieved with modern detector/radiometer standards than traditionally used source standards (blackbodies and lamps
Figure 1. Class of optical setup considered in this work. The aperture can be limiting (as shown in this case) or nonlimiting.

Diffraction effects in radiometry

Ongoing
Essentially, classical radiometry relies on geometrical optics (to relate source radiance), geometrical aspects of an optical layout, and the irradiance at the detector. One considers the propagation of radiation from points on the surface of the source to points on the surface of the detector. In
Zone Plate Schematic

EUV Zone Plates for Compact Solar Radiometer

Ongoing
A zone plate is an optical element used to separate and focus individual wavelengths of light. The zone plate consists of small circular rings that are opaque to the light separated by gaps, which are transparent. The incident light diffracts from the zone plate at an angle that depends on the
silicon photodiode

Extreme Ultraviolet Detector Calibration Service

Ongoing
The National Institute of Standards and Technology (NIST) has a wide variety of programs for the calibration of instruments and components for space-based research in the extreme ultraviolet (EUV). Many of these programs have been in existence since the 1960s, and have provided calibration support
Reflectance of two materials

Extreme ultraviolet optical constants

Ongoing
Measurements of EUV optical constants are often made by measuring the absorption or near-normal-incidence reflectivity, then performing transforms to obtain both the real and imaginary parts of the index. These sorts of measurements have considerable uncertainty because they require knowledge of
A high-finesse Fabry-Perot interferometer

Fabry-Perot Displacement Interferometry

Ongoing
Fabry-Perot interferometry has the highest resolution of any displacement sensor, below one picometer, and yet may be used to measure displacements of many centimeters. Equally important, it enables a natural and direct link to the SI unit of length, defined in terms of the speed of light. We are
bolometer

Far infrared remote sensing

Ongoing
The Total Solar Irradiance and the outgoing Earth radiance are long term measurements that have been monitored from space for over 40 years. Microfabricated, absolutely calibrated bolometers with vertically-aligned carbon nanotubes that are developed by this project provide a more accurate and more
fiber frequency comb design

Fiber-optic Frequency Comb Development

Ongoing
Frequency combs have found a wide range of applications beyond just optical metrology. Applications include laser ranging, precision molecular spectroscopy in the lab and over the air, optical timing distribution, low-noise microwave generation and support for optical clocks. All these applications
single_photon_QFT_schematic

Frequency Conversion Interfaces for Photonic Quantum Systems

Ongoing
Our research on quantum frequency conversion follows two main tracks. First, we combine relatively mature frequency conversion technology based on periodically-poled lithium niobate waveguides with quantum light generated by single semiconductor quantum dots in proof-of-principle experiments that
High Amplification Laser-pressure Optic

High Amplification Laser-pressure Optic (HALO)

Ongoing
We have assembled a high-accuracy laser power meter based on radiation pressure with multiple reflections of the laser on the sensing mirror. A custom electrostatic force balance supports a high-reflectivity sensing mirror upon which a high-power continuous wave laser beam is incident at ~ 45
x-ray laser welding setup

High-Power Laser Applications

Ongoing
Measurement challenges Traditional measurements of laser power or energy involve absorbing the laser light and measuring the resulting temperature increase of the absorber. However, as the power and total energy delivered by these lasers increases, thermal management, absorber size, and response