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Scott Diddams (Assoc)

Physicist and NIST Fellow

Scott Diddams is a Fellow of the National Institute of Standards and Technology (NIST) and an Adjoint Professor at the University of Colorado. He carries out experimental research in the fields of precision spectroscopy and metrology, nonlinear optics, microwave photonics and ultrafast lasers.  He received the Ph.D. degree from the University of New Mexico in 1996.  From 1996 through 2000, he did postdoctroral work at JILA, NIST and the University of Colorado.  Since 2000, Diddams has been a staff physicist at NIST.  Present research focuses on the development of optical frequency combs and their use in optical clocks, tests of fundamental physics, novel spectroscopy in the visible and mid-infrared, and ultralow noise frequency synthesis.  In recent years, special attention has been given to infrared frequency comb sources as well as high repetition rate laser-based and microresonator frequency combs, which are being explored for applications in clocks, frequency and waveform synthesis, and astronomy.  

Selected publications are below and a full list can be found here.


​​​​​​IEEE Rabi Award (2017)

Jacob Rabinow Award for Innovation (2014)

Moore Distinguished Scholar in Engineering and Applied Science, Caltech (2012-13)

Department of Commerce Silver Medal Award for Scientific/Engineering Achievement (2011)

Arthur S. Flemming Award (2010)

Fellow of Optical Society of America (2009)

Fellow of American Physical Society (2009)

European Frequency and Time Forum (EFTF) Young Scientist Award (2007)

Presidential Early Career Award for Scientists and Engineers (2003).

Department of Commerce Gold Medal Award for Scientific/Engineering Achievement (2001).

National Research Council Postdoctoral Fellow (1998-2000). 

Selected Publications

An Optical Clock Based on a Single Trapped Hg+ Ion

Scott A. Diddams, T Udem, K R. Vogel, Christopher W. Oates, E A. Curtis, W D. Lee, Wayne M. Itano, Robert E. Drullinger, James C. Bergquist, Leo W. Hollberg
Microwave atomic clocks have been the de facto standards for precision time and frequency metrology over the past 50 years, finding widespread use in basic

Microresonator based optical frequency combs

Scott A. Diddams, T. J. Klippenberg
Optical frequency combs based on mode-locked laser sources have provided unprecedented measurement capabilities for optical frequencies, enabling new

The evolving optical frequency comb

Scott A. Diddams
Much as natural historians search for the first roots of our human race, curiosity drives the laser scientist to pursue the roots of his or her own field. This

Generation of Ultrastable microwaves via optical frequency division

Tara Fortier, Matthew S. Kirchner, Jennifer A. Taylor, James C. Bergquist, Yanyi Jiang, Andrew Ludlow, Christopher W. Oates, Till P. Rosenband, Scott Diddams, Franklyn Quinlan, Nathan D. Lemke
A frequency-stabilized femtosecond laser optical frequency comb serves as a source of microwave signals having very low close-to-carrier phase noise. Comparison

Octave-spanning dual frequency comb spectroscopy in the molecular fingerprint region

Henry R. Timmers, Abijith S. Kowligy, Alexander J. Lind, Flavio Caldas da Cruz, Nima Nader, Myles C. Silfies, Thomas K. Allison, Gabriel G. Ycas, Peter G. Schunemann, Scott B. Papp, Scott A. Diddams
Spectroscopy in the molecular fingerprint spectral region (6.5-20 $\mu$m) yields critical information on material structure for physical, chemical and


Dual-comb correlation spectroscopy of thermal light

Eugene Tsao, Alexander Lind, Connor Fredrick, Ryan Cole, Peter Chang, Kristina Chang, Dahyeon Lee, Matthew Heyrich, Nazanin Hoghooghi, Franklyn Quinlan, Scott Diddams
The detection of light of thermal origin is the principal means by which humanity has learned about our world and the cosmos. In optical astronomy, in

Multi-harmonic near-infrared–ultraviolet dual-comb spectrometer

Kristina Chang, Daniel Lesko, Carter Mashburn, Peter Chang, Eugene Tsao, Alexander Lind, Scott Diddams
Dual-comb spectroscopy in the ultraviolet (UV) and visible would enable broad bandwidth electronic spectroscopy with unprecedented frequency resolution

Photonic chip-based low noise microwave oscillator

Igor Kudelin, William Groman, Scott Diddams, Dahyeon Lee, Megan Kelleher, Takuma Nakamura, Charles McLemore, Franklyn Quinlan, Qing-Xin Ji, Joel Guo, Andrey Matsko, John Bowers, Kerry Vahala, Warren Jin, Lue Wu, Yifan Liu, Wei Zhang, Steven Bowers, Joe Campbell, Pedram Shirmohammadi, Samin Hanifi, Haotian Cheng, Naijun Jin, Sam Halliday, Zhaowei Dai, Chao Xiang, Vladimir Iltchenko, Owen Miller, Peter Rakich
Numerous modern technologies are reliant on the low-phase noise and timing stability performance of microwave signals. Substantial progress has been made in the

Low-noise microwave generation with an air-gap optical reference cavity

Yifan Liu, Dahyeon Lee, Takuma Nakamura, Naijun Jin, Haotian Cheng, Megan Kelleher, Charles McLemore, Igor Kudelin, William Groman, Scott Diddams, Peter Rakich, Franklyn Quinlan
We demonstrate a high finesse, microfabricated mirror-based, air-gap cavity with volume less than 1 ml, constructed in an array, that can support low-noise

Patents (2018-Present)

Delivering Signals To Cryogenic Environments Via Photonic Links

NIST Inventors
Franklyn Quinlan , Scott Diddams , Joe Aumentado , Florent Lecocq and John Teufel
An operational environment is disclosed herein that includes a cryogenic environment and a signal source. The cryogenic environment includes a signal target, an optical link, signal converter devices, and an electrical link. Outside of the cryogenic environment, the signal source generates an

Methods And Apparatus For Generating Mid-Infrared Frequency Combs

NIST Inventors
Scott Diddams , Scott Papp , Abijith Kowligy and Alexander Lind
Apparatus and methods for generating mid-IR frequency combs using intra-pulse DFG. A mode-locked pulse generation laser generates near-IR pulses which are amplified. The amplified pulses are spectrally broadened by a nonlinear element, for example a normal dispersion highly nonlinear fiber (ND-HNLF)

Ultrafast Electro-optic Laser

NIST Inventors
Scott Papp , Scott Diddams and David Carlson
An ultrafast electro-optic laser makes a stabilized comb and includes: a comb generator that produces a frequency comb; a dielectric resonant oscillator; a phase modulator in communication with the dielectric resonant oscillator; an intensity modulator in communication with the phase modulator; an

Optical Reference Cavity

NIST Inventors
Franklyn Quinlan , Scott Diddams and Andrew Ludlow
An optical reference cavity includes: a cell that includes: a cylindrical body; end faces; an optical canal having an interior cylindrical geometry; and an exterior surface having an exterior cylindrical geometry; mirrors disposed on the end faces; an aspect ratio that is less than 1; a compression
Created March 26, 2019, Updated December 9, 2022