Sub-Standard Quantum Limit in Suspended Interferometers

Sub-Standard Quantum Limit in Suspended Interferometers

Probing the limits imposed on precision interferometry with suspended macroscopic mirrors by the quantum nature of light and aim to surpass them.

Contributions to QuantumFrontiers

  • Establishment of a long-term, internationally unique testing facility
  • Development of measurement techniques surpassing the Standard Quantum Limit (SQL) of optical interferometry 
  • Interfacing of microscopic and table-top quantum opto-mechanics with large scale gravitational wave detector scale instruments
  • Enhancement of current and future gravitational wave detector sensitivity to increase their range towards cosmological distances
  • Foster knowledge transfer among Quantum Frontiers groups on techniques to suppress noise in precision experiment.

Collaborative Innovation

  • Focus on developing technologies and techniques to suppress classical and technical noise sources to below quantum noise in precision measurements, with a particular emphasis on gravitational-wave-detector-like laser interferometry with suspended optics. (Lück, Wu, Valbruch AEI, LUH)
  • Investigating and developing new technology to suppress classical and technical noise in ground based interferometric gravitational wave detectors (Heurs, Willke AEI, LUH)
  • Constructing the Sub-SQL Interferometer: a 10m Fabry-Perot Michelson interferometer, nominally limited by SQL in the band between 60 and 200 Hz using macroscopic test masses of 100 g. (Lück, Wu, AEI, LUH)
  • Improving techniques to suppress classical and technical noise below quantum noise, for example: improving seimsic isolation platforms, suspended optics, laser noise, and environmental noise. (Lück, Wu, Willke, Heurs Valbruch, AEI, LUH)

Scientific Output

  • Publications

    Brown DD, Jones P, Rowlinson S, Leavey S, Green AC, Töyrä D et al. PYKAT: Python package for modelling precision optical interferometers. SoftwareX. 2020 Dec;12. 100613.


    Kirchhoff R, Mow-Lowry CM, Bergmann G, Hanke MM, Koch P, Köhlenbeck SM et al. Local active isolation of the AEI-SAS for the AEI 10 m prototype facility. Classical and quantum gravity. 2020 May 4;37(11). 115004.

    Koch P, Cole GD, Deutsch C, Follman D, Heu P, Kinley-Hanlon M et al. Thickness uniformity measurements and damage threshold tests of large-area GaAs/AlGaAs crystalline coatings for precision interferometry. Optics express. 2019 Dec 9;27(25):36731-36740.


TG Members

  • Involved Members and their Relevant Expertise
    Members Institution Relevant Expertise
    David Wu, Leader LUH Sub-Standard Quantum Limit Interferometry
    Harald Lück AEI Next Generation Gravitational Wave Observatories; Sub-Standard Quantum Limit Interferometry
    Matteo Carlassara AEI Multi-stage suspended optics
    Michèle Heurs LUH Backaction-Evading Techniques
    Benno Willke AEI Squeezed Light Sources; Advanced Light Sources
    Philip Koch AEI Multi-stage suspended optics; Vacuum outgassing test chamber; Optical scattering of optical components
    Johannes Lehmann AEI Precision laser interferometry; Multi-stage suspended optics; Seismic isolation platforms; Vacuum compatable sensors and actuators
    Juliane von Wrangel AEI Precision glass welding and bonding of quasi-monolithic suspended mirrors
    Janis Wöhler AEI Precision laser interferometry; Coating thermal noise measurements
    Henning Vahlbruch AEI Squeezed states of light
    Sara al-Kershi AEI Multi-stage suspended optics
    Firoz Khan AEI Optical scattering of optical components; Scattered light mitigation
    Paul Hapke AEI Steady state simulations of interferometers using FINESSE