The flexible network design can simplify accurate comparisons of the latest atomic clocks operating at different frequencies and in different locations. The research also may have applications in remote sensing and secure communications.
Described in the May issue of Nature Photonics,* the prototype NIST network demonstrates the first remote synchronization of light waves from two "frequency combs"—advanced laboratory tools for precisely measuring frequencies of light. The two combs have fine "teeth" marking precise frequencies in different but overlapping bands. If light waves at identical frequencies are merged, they can either overlap exactly or be "out of phase" (that is, their oscillations are at the same frequency but start at different times). Light waves at different frequencies never overlap exactly but, with great effort, can be made to overlap out of phase in the same patterns in repeated experiments. The NIST network is designed to do exactly that, thus reducing channel "noise" that would result from mismatches. The stability of the lasers and low "jitter" of the synchronized waves means the original signal character is always preserved.
The network also showcases record performance in a frequency comb produced from an erbium fiber laser, an alternative to the original frequency comb generated from a titanium-sapphire crystal, also developed at NIST. Scientists recently reduced the noise in the fiber-based comb enough to improve its stability 30-fold, achieving performance comparable to the state-of-the-art Ti:Sapphire frequency comb used as the second comb in the new NIST network. Fiber-based frequency combs have the potential to be more compact and less expensive; they also measure the lower, near-infrared frequencies of light that are used in telecommunications.
The prototype network spans three-quarters of a kilometer and connects three different laboratories on the NIST Boulder, Colo., campus. The designers say it could be extended to 50 km or more without any loss in performance. To showcase the capability of the two frequency combs (which operate on different principles) to precisely compare vastly disparate optical frequencies across great distances, both combs are stabilized by the same source of 1126 nm laser light, so that each tooth of each comb is locked to a single frequency. In addition, laser light at 1535 nm laser, stabilized by one comb, is compared to 1535 nm light generated from the second comb, and the stability of the beat frequency (representing the difference between them) is analyzed to evaluate network performance.
Laura Ost | EurekAlert!
Snake-inspired robot uses kirigami to move
22.02.2018 | Harvard John A. Paulson School of Engineering and Applied Sciences
Camera technology in vehicles: Low-latency image data compression
22.02.2018 | Fraunhofer-Institut für Nachrichtentechnik, Heinrich-Hertz-Institut, HHI
A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.
In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...
A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.
By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...
Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
23.02.2018 | Physics and Astronomy
23.02.2018 | Health and Medicine
23.02.2018 | Physics and Astronomy