Tags - (11) frequency comb metrology

Department(s)/lab(s): School of Physics | Berengut Atomic Structure and Clocks Theory Group @ UNSW
Summary:

Berengut works on the atomic structure theory underpinning next-generation clocks: highly charged ions, whose optical transitions are both extremely narrow and exceptionally sensitive to variation of fundamental constants and to new physics, and the thorium-229 nuclear clock. He identifies which ionic species and transitions maximise sensitivity to the physics of interest while remaining experimentally accessible, and computes the many-body structure needed to interpret them β€” work that has directly guided the experimental HCI clock programmes at PTB, MPIK and NIST. Positioned against the established body of NV-ensemble quantum sensing work β€” DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity β€” clocks and magnetometers are the two great classes of quantum sensor; his work is on the frequency side of the same estimation problem that fixes pT/sqrt(Hz) performance on the magnetic side. Theory PI with close experimental collaborations.

Department(s)/lab(s): School of Physics / Sydney Institute for Astronomy | Sydney Astrophotonic Instrumentation Laboratory (SAIL) @ USyd
Summary:

Bland-Hawthorn founded the field of astrophotonics and directs SAIL. The core idea is to replace bulk-optic astronomical instruments with single-mode photonic devices: the photonic lantern (an adiabatic multimode-to-single-mode transition that lets a seeing-limited telescope beam be fed into single-mode circuitry), fibre Bragg grating OH-suppression filters that notch out the ~100 atmospheric emission lines swamping the near-infrared, integral-field hexabundles, photonic combs and integrated spectrographs. He also leads Galactic archaeology work (GALAH, S5). Positioned against the established body of NV-ensemble quantum sensing work β€” DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity β€” SAIL is where a quantum-sensing physicist's instincts about single-mode optics, photon budgets and noise floors transfer most directly into astronomy β€” the entire discipline exists because photon-starved measurements need front-end optics designed at the fundamental limit, exactly as with pT/sqrt(Hz) magnetometry. Excellent pivot target; large group, deep fabrication resources.

Department(s)/lab(s): Applied Physics | Byer Group @ Stanford
Summary:

Byer's long-running program in nonlinear optics and laser physics has produced key technologies for precision measurement, including low-noise laser sources, optical materials, and interferometric techniques that underpin gravitational-wave detectors and frequency metrology.

Department(s)/lab(s): Electrical Engineering & Computer Sciences | Z. Chen Photonics Lab @ UCB
Summary:

Chen (PhD, Max Planck Institute of Quantum Optics) develops chip-scale frequency-comb sources for precision metrology and dual-comb spectroscopic sensing, and is now extending integrated thin-film lithium-niobate photonics toward on-chip squeezed-light generation for quantum-enhanced sensing alongside photonic AI accelerators. The lab is actively recruiting postdocs.

Department(s)/lab(s): Physics – Institute for Quantum Electronics | Quantum Optoelectronics Group (Faist Group) @ ETH Zurich
Summary:

Faist is the inventor of the quantum cascade laser (QCL, 1994 at Bell Labs) and leads the Quantum Optoelectronics Group at ETH. Research directions: (1) QCL frequency combs β€” ring QCLs demonstrate dissipative Kerr solitons in the THz (Science Advances 2023), key for broadband integrated mid-IR spectrometers; (2) Dual-comb spectroscopy β€” two co-integrated ring QCLs for ultrafast molecular fingerprinting; (3) Quantum cascade detectors β€” strain-compensated InGaAs/InAlAs QCDs for short-wave mid-IR (<4 Β΅m) sensing; (4) THz strong-coupling β€” ultrastrongly coupled 2DEG in cavities for quantum photonics; (5) Astrophysical heterodyne receivers β€” double-metal QCL Josephson mixers. Spin-off: IRsweep (mid-IR dual-comb systems) and Alpes Lasers (QCL commercialisation). FIRST Center head at ETH.

Department(s)/lab(s): Physics | Hollberg Group @ Stanford
Summary:

Hollberg works on optical atomic clocks, laser frequency stabilization, and frequency-comb metrology, including chip-scale and field-deployable clock technology with applications to relativistic geodesy and precision tests of fundamental physics.

Department(s)/lab(s): Physics – Institute of Physics (IPHYS) | Laboratory of Photonics and Quantum Measurements (K-Lab) @ EPFL
Summary:

Kippenberg leads the Laboratory of Photonics and Quantum Measurements (K-Lab) at EPFL, pioneer of chip-scale microresonator frequency combs and cavity optomechanics. Research directions: (1) Soliton microcombs β€” dissipative Kerr solitons in Si3N4 microresonators for massively parallel coherent optical communications, precision ranging/LiDAR (Science 2018, Nature 2017); dual-chirped microcomb parallel ranging at megapixel rates; (2) Room-temperature quantum optomechanics β€” phononic-crystal-patterned Si3N4 membrane-in-the-middle cavity reduces frequency noise 700Γ—, observing quantum backaction at room temperature (Nature 2024); (3) Superconducting circuit optomechanics β€” topological lattices, electromechanical sensing (Nature 2022); (4) Free-electron–photon interactions in microresonators. Spin-off companies and strong industry ties. Over 85,000 citations, h-index ~80.

Department(s)/lab(s): Physics | SYRTE - Optical Frequency Metrology Team @ CNRS
Summary:

Le Targat co-leads SYRTE's Optical Frequency Metrology team, which built and continuously operates two independent strontium optical lattice clocks alongside a mercury lattice clock, comparing them at the 10^-16 to 10^-17 level and to SYRTE's caesium fountain primary standards. This work underpins the prospective redefinition of the SI second on an optical transition and supports frequency-transfer, geodesy and fundamental-physics tests via fiber links to other French metrology laboratories.

Department(s)/lab(s): Physics & Astronomy | Schuessler Laser Spectroscopy & Ion Trap Group @ TAMU
Summary:

Schuessler combines optical frequency combs with cavity-enhanced and mid-IR spectroscopy for ultrasensitive trace-gas and isotopic detection, and runs ion-trap precision mass/laser spectroscopy of exotic species. In the broader landscape of NV-centre ensemble quantum sensing (DEER, nano-NMR, T1 relaxometry) operating near pT/sqrt(Hz) sensitivity, this work is a comb-metrology counterpart to spin-based chemical sensing.

Department(s)/lab(s): School of Physics | Tinney Exoplanetary Science Group @ UNSW
Summary:

Tinney is an exoplanet hunter who builds the spectrographs he uses. He leads Veloce, the high-resolution, ultra-stable echelle spectrograph on the Anglo-Australian Telescope, whose entire purpose is to measure stellar radial velocities at the ~1 m/s level β€” a fractional wavelength shift of order 10^-9 β€” which requires obsessive control of thermal, mechanical and illumination systematics plus laser-comb or etalon wavelength calibration. He also works on brown dwarfs and on disentangling stellar activity from planetary signals. Positioned against the established body of NV-ensemble quantum sensing work β€” DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity β€” precision radial velocity is a frequency-metrology problem dressed as astronomy: like a pT/sqrt(Hz) magnetometer, the instrument's raw sensitivity was solved years ago and all remaining progress is in systematics and calibration. Good pivot target for a metrology-trained candidate.