NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
All-fiber frequency comb at 2 µm providing 1.4-cycle pulses
Published
Author(s)
Sida Xing, Abijith S. Kowligy, Daniel Lesko, Alexander Lind, Scott Diddams
Abstract
We report an all-fiber approach to generating sub-2-cycle pulses at 2 µm and a corresponding octave-spanning optical frequency comb. Our configuration leverages mature erbium:fiber laser technology at 1.5 µm to provide a seed pulse for a thulium-doped fiber amplifier that outputs 330 mW average power at a 100 MHz repetition rate. Following amplification, nonlinear self-compression in fiber decreases the pulse duration to 9.5 fs, or 1.4 optical cycles. The spectrum of the ultrashort pulse spans from 1 to beyond 2.4 µm and enables direct measurement of the carrier-envelope offset frequency. Our approach employs only commercially available fiber components, resulting in a design that is easy to reproduce in the larger community. As such, this system should be useful as a robust frequency comb source in the near-infrared or as a pump source to generate mid-infrared frequency combs.
Xing, S.
, Kowligy, A.
, Lesko, D.
, Lind, A.
and Diddams, S.
(2020),
All-fiber frequency comb at 2 µm providing 1.4-cycle pulses, Optics Letters, [online], https://doi.org/10.1364/OL.391486, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=929699
(Accessed October 17, 2025)