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Physics

Optical physics and communications

Projects/Programs

Displaying 1 - 25 of 58
Atmospheric Particles

Analysis and Modeling of Atmospheric Particles to Assess Effects on Climate

Ongoing
Spectral data from satellite and ground-based remote sensing instruments are used to monitor the effects of atmospheric aerosols on climate. Determinations of how aerosols interact with sunlight or infrared radiation from Earth’s surface rely upon an aerosol model that approximates the sizes, shapes
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
ROSI

Building the next generation reference reflectometer

Ongoing
Have you ever wondered why some objects appear glossy, and others diffuse? Or thought about the complexity of characterizing the way light reflects from an object under different illumination and viewing angles and at different wavelengths in order to realistically render it in a computer simulation

Calculation of optical constants and dielectric response

Ongoing
By optical properties, we mean those of the following sort: the index of refraction n and the index of absorption k, from which one can calculate the dielectric function, loss function, absorption coefficient, reflectance, and so forth from standard formulas. All of these quantities, it should be

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
color and appearance diagram

Color and appearance

Ongoing
The quality of an object—be it fruit at the grocery store, clothes in the department store, or a new car on the dealer's lot—is often judged by its color and appearance. Appearance greatly influences a customer's judgement of the quality and acceptability of manufactured products, as yearly there is
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
joint quantum institute

Designing the Nanoworld: Nanostructure, Nanodevices, and Nano-optics

Ongoing
Developing and exploiting nanodevices for quantum and nanotechnologies requires nanoscale and atomic scale modeling of ultrasmall structures, devices, their operation, and their response to probes. Key challenges of understanding physics at the quantum/classical interface and measurement at the

Detector-based color scale

Ongoing
The expanded uncertainty of the NIST primary color-temperature lamp-standards is 8 K ( k=2). However, both the long-term stability and the spectral distribution of the lamps can significantly change with burning time. By performing the tristimulus colorimeter calibrations against detector standards
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
bolometer

Earth Energy Budget

Ongoing
The Earth Energy Balance is a fundamental climate measurement that has 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 compact method for
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
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
infrared starlight

Frequency Comb Calibration of Astronomical Spectrographs

Ongoing
A powerful technique for finding exo-planets is based on measuring the tiny Doppler shifts in the light from a star that is induced by the presence of orbiting planets. While many exo-planets have been discovered using this Doppler radial velocity (RV) technique, it remains a significant technical
CombSpec1

Frequency Comb Spectroscopy

Ongoing
Erbium mode-locked fiber lasers are a mature technology that provide a means to build robust optical frequency combs centered near 1550 nm. One research focus of our group is to extend the optical bandwidth of Er fiber-based combs into the near- to mid-infrared wavelength region of 1000 to 5000 nm
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
dual-comb spectroscopy illustration

Frequency-comb-based Spectroscopy (Dual-Comb Spectroscopy)

Ongoing
Fully stabilized frequency combs provide a broadband spectral output that is comprised of a series of narrow spectral lines or “teeth”. “Dual comb spectroscopy” provides one method to harness these properties for broadband spectroscopy. It allows the user to read-out the spectrum of a gas mixture on

Fundamentals of Deformation

Ongoing
• We have provided general users from industry, academia and national laboratories with a completely new class of X-ray imaging techniques for materials studies (ultra-small-angle X-ray scattering imaging), that we developed from basic concept to DOE-supported operations at the Advanced Photon