Project C8;     (2010 - 2014)

 Project List   Abstracts   All Publications 

A1  A2  A4  A5  A7  B1  B2  B3  B4  B5  B6  B7  B8  B9  B10  C1  C2  C3  C4  C5  C6  C7  C8  C9  C10  Ö


Nonclassical readout for gravitational wave detectors

    Principal Investigators: Roman Schnabel, Karsten Danzmann

The new project C8 researches and experimentally demonstrates nonclassical readout schemes based on quantum entangled light. The goal is the sensitivity improvement of future ground-based gravitational wave detectors using ultra-high laser powers. When increasing the laser power a problem arises because the amount of scattered photons at the interferometer readout port also increases. Current readouts are not able to distinguish between signals arising from scattered photons and signals arising from gravitational waves. In this project entangled light will be used to experimentally demonstrate an interferometer readout that is able to distinguish between scattered photons and gravitational wave signals without deteriorating the overall detector sensitivity that might already be enhanced with squeezed light.



  Roman Schnabel   Professor, PI 2010
  Karsten Danzmann   Professor, PI 2010
  Joeran Bauchrowitz   PhD Student, 2010

Former Associates
  Sebastian Steinlechner   PhD Student, 2010


[1] Advanced techniques in GEO 600
C. Affeldt, K. Danzmann, K. L. Dooley, H. Grote, M. Hewitson, S. Hild, J. Hough, J. Leong, H. Lück, M. Prijatelj, S. Rowan, A. Rüdiger, R. Schilling, R. Schnabel, E. Schreiber, B. Sorazu, K. A. Strain, H. Vahlbruch, B. Willke, W. Winkler, and H. Wittel, Class. Quantum Grav. 31 224002

[2] ,

[3] Strong EPR-steering with unconditional entangled states,
S. Steinlechner, J. Bauchrowitz, T. Eberle, and R. Schnabel, Phys. Rev. A 87, 022104

[4] First Long-Term Application of Squeezed States of Light in a Gravitational-Wave Observatory
H. Grote, K. Danzmann, K. L. Dooley, R. Schnabel, J. Slutsky, H. Vahlbruch, Phys. Rev. Lett. 110, 181101

[5] Balanced Homodyne Detection of Optical Quantum States at Audio-Band Frequencies and Below
M. S. Stefszky, C. M. Mow-Lowry, S. S. Y. Chua, D. A. Shaddock, B. C. Buchler, H. Vahlbruch, A. Khalaidovski, R. Schnabel, P. K. Lam and D. E. McClelland, Class. Quantum Grav. 29, 145015

[6] A gravitational wave observatory operating beyond the quantum shot-noise limit
The LIGO Scientific Collaboration, Nature Physics