The Optical Frequency Measurements Group conducts cutting-edge research focused on generating stable optical frequencies and developing tools for precisely measuring optical frequencies, which have the potential to achieve unprecedented timing performance. We construct different types of atomic clocks to generate optical frequencies that have demonstrated a fractional instability approaching 1 part in 1018 and an absolute fractional frequency uncertainty approaching 10-16. We develop laser frequency combs to connect stable optical frequencies to each other and to microwave sources with an imprecision below 1 part in 1019. These state-of-the-art frequency combs are also developed for other important applications, including ultra-low noise microwave generation, mid-IR molecular spectroscopy, optical waveform generation,and calibration of astronomical spectrographs for searches for exo-planets. Micro-resonators are being investigated as a promising platform to move frequency combs from laboratory devices to chip-integrated devices for science and metrology.
Group activities include:
Yb Optical Lattice Clock By tightly confining tens of thousands of atoms in an optical standing wave (lattice), we construct state-of-the-art atomic clocks capable of unprecedented stability and low uncertainty.
Femtosecond-laser Optical Clockwork We have developed mode-locked, fs-lasers that act as optical frequency dividers, capable of linking optical frequencies to other optical frequencies and to the microwave domain with a demonstrated fidelity of 1 part in 1019.
Optical and Microwave Waveform Synthesis We use fs-laser combs to generate optical and microwave waveforms with unprecedented noise performance.
Frequency Comb Spectroscopy We use optical frequency combs to perform precision spectroscopy in the visible and, more recently, mid-IR domains, for rapid, high sensitivity, broadband gas detection.
Frequency Comb Calibration of Astronomical Spectrographs We have constructed portable frequency combs that have provided in-situ calibration of astronomical spectrographs, to aid in the search for exo-planets.
Fs-laser Source Development Fs-laser development is an important part of our Group's research and has led to quieter, higher repetition-rate laser sources, both solid-state and fiber-based, for advanced frequency comb applications.
Microresonator Device Research With micro-resonators (fabricated in house or by collaborators) we are developing microcombs, integrated reference cavities and low-noise laser sources. The goal is to understand the fundamental and technical aspects critical for implementing precision time and frequency metrology in chip-scale devices.
Ca Optical Frequency Standard A simple, compact alternative to the highest performing optical atomic standards, the Ca clock uses a thermal beam of neutral atoms with one or two lasers to achieve high stability in a potentially fieldable instrument.
Calcium Optical Beam Clock—Our Group is developing compact, high stability optical clocks for real world applications. Current versions use one or two laser systems and a thermal calcium atomic beam to achieve high stability …
Time and Frequency Division
Apply for an NRC postdoc in optical atomic clock or fs-laser frequency comb research. Application deadlines are February 1 and August 1 annually (but inquire well in advance).
Postdoctoral, Visiting Scientist, and Graduate Positions
Our Group has periodic openings for Postdoctoral Fellows, Visiting Scientists, and Graduate Students. Please contact us for more information.
Summer program at NIST-Boulder for undergraduates in science, engineering, and mathematics. The application deadline is February 15 annually.