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Physics

Time & frequency

Projects/Programs

Displaying 1 - 24 of 24

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
chip scale atomic beam clock

Compact Cold Atom Instruments

Ongoing
Chip-scale laser cooling This project develops technologies to achieve chip-scale laser cooling, beyond direct miniaturization of existing laboratory techniques. This includes development of the vacuum technology for realizing low power, passively pumped ultra-high vacuum chambers [1,2] and novel
optical clock

Compact strontium optical clock with integrated photonics

Ongoing
The development of a liter-scale apparatus to produce Sr, would enable highly accurate, transportable optical clocks based on their ultra-narrow optical transition. However, straightforward miniaturization of the traditional optical infrastructure necessary to implement multi-step laser cooling has
Compact ultrastable optical references illustration

Compact Ultrastable Optical References

Ongoing
At the heart of any stable laser is a reference cavity resonator. By locking a laser’s frequency to a reference cavity mode, the laser inherits the resonator’s stability. These stable lasers can then be used in various sensing and spectroscopy applications, including in optical atomic clocks and
Cryogenic Photonic Interconnects illustration

Cryogenic Photonic Interconnects

Ongoing
Microwave photonics, where optical systems are employed to transport, filter, generate, or otherwise process microwave and millimeter wave signals, takes advantage of the large bandwidth, low loss, and low noise of optical systems, as well as the long reach of optical fiber interconnects. We are

Femtosecond-Laser Frequency Combs for Optical Clocks

Ongoing
The self-referenced optical frequency comb, which our NIST/University of Colorado collaboration first demonstrated in 1999, ushered in a revolution in optical frequency metrology. The frequency comb made it possible to directly count optical cycles with femtosecond resolution using a compact and
Web interface to control and monitor the servo with interactive blocks

Field Programmable Gate Array (FPGA) Designs for Metrology

Ongoing
Until recently, the precision measurement of phase noise, spectral purity, and related quantities had been a challenging process, with only a handful of qualified experts in the world. However, Field Programmable Gate Array (FPGA) based measurement systems, similar to software defined radio (SDR)
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
NIST FMAS

Frequency Measurement and Analysis Service (FMAS)

Ongoing
Subscribers to the NIST service receive a complete frequency measurement system which includes everything needed to make precision frequency measurements that are traceable to NIST. An easy-to-read instruction manual makes installation a snap. Once the system is installed, it's easy to get started
Cryogenic sapphire optical cavity

Laser Stabilization and Coherence with Optical Resonators

Ongoing
Coherent laser interrogation of the narrowband electronic ‘clock’ transition is required to realize the very high spectroscopic resolution that make optical clocks so precise. At the same time, phase fluctuations in the laser interrogation can compromise the frequency stability of the optical clock
5 MHz Graph of phase noise vs. offset frequency showing NIST synthesized signal, Wenzel OXCO, and BVA oscilloquartz.

Low-Phase Noise Frequency Synthesis

Ongoing
Frequency synthesis plays an essential role in virtually all present-day commercial, industrial, and military technologies. State-of-the-art low-noise frequency synthesis is a crucial technical asset to high-resolution imaging and radar, high-speed telecommunications, and efficient management of the
Fiber magnetometer

Microfabricated Atomic Sensors

Ongoing
Our program aims to develop sensors that can simultaneously achieve high absolute scalar accuracy and vector magnetic field measurement without the need for calibrations. An atomic magnetometer relies on the fundamental constants of nature to translate magnetic fields into a measurable Larmor
Microcombs2

Microresonator Device Research

Ongoing
In the last few years a revolutionary paradigm for optical frequency combs and ultrastable continuous-wave lasers has emerged based on nonlinear optics in optical microresonators. Such microresonator devices can now be realized using millimeter-scale, chip-based photonic integrated circuits
BO+WKB model

Optical Clock Atomic Structure and Theory

Ongoing
An atomic clock aims to realize the intrinsic ticking rate of an atom. This ticking rate (i.e., frequency) is associated with a transition between two quantum levels of the atom, where each level corresponds to a different configuration of the electrons around the nucleus. Atomic clocks derive their
lownoisemicrowave

Optical and Microwave Waveform Synthesis

Ongoing
A typical optical frequency comb consists of thousands to millions of phase coherent modes (the "teeth" of the comb) that can all be used to synthesize precisely controlled electromagnetic waveforms. Our main research thrust in this area has been focused on the generation of microwave and millimeter
OTWTFT

Optical Two-way Time-frequency Transfer

Ongoing
Researchers in the Fiber Sources and Applications Group have been developing the technique of “Optical Two-Way Time-Frequency Transfer” (OTWTFT) which can link time between distant clocks to the femtosecond level over free-space links. Optical clock networks could enable tests of fundamental physics
Image of AM/PM Noise Calibration Standard device made by NIST

Phase and Amplitude Noise Calibration Services

Ongoing
The primary responsibility of the Phase Noise Metrology Group is to develop and provide calibration services for industrial, military, and commercial organizations to support the core mission of NIST. The PM and AM noise measurements require traceability and certification of devices such as phase
atom chamber

Portable Optical Lattice Clock

Ongoing
Exploiting their very high precision, atomic clocks today are used extensively in demanding timekeeping applications. These include a variety of navigation, communication, and remote sensing and imaging applications. The very best atomic clocks today, optical clocks, are among the most precise

Precision Measurement Grants Program

Ongoing
If funding is available, one new grant in the amount of $50,000 per year will be awarded for the initial period of October 1 through September 30 of the following year. The award may be continued for up to two additional years; however, future or continued funding will be at the discretion of NIST
NIST disciplined clock chassis

Time Measurement and Analysis Service (TMAS)

Ongoing
The TMAS meets the requirements of any facility or organization that needs to maintain a high accuracy time standard. TMAS customers include calibration and metrology laboratories, telecommunication providers, instrumentation manufacturers, military installations, defense contractors, government
trap assembly

Trapped Sr+ ion clock; a secondary realization of the SI second

Ongoing
The single 88Sr + clock is attractive for both its frequency accuracy and for its relative simplicity. The 674 nm clock transition has been independently studied at several NMI’s at the 10 -17 level [1-4]. Advances in light source technology [5,6] may allow operation with just two lasers: one for
Computer-generated image showing a cross-shaped gold metal cutout on a red mount in between two metal posts, with an inset magnifying the cutout to show blue and yellow balls at the center.

Trapped Ion Optical Clocks

Ongoing
This project uses techniques from quantum information science to enable precision metrology. We use the dipole-forbidden 1S 0 - 3P 0 transition in singly-ionized aluminum as an stable frequency reference (natural linewidth ~8 mHz), which we detect using quantum logic spectroscopy with a second ion