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arXiv · 1512.01216

First measurements of high frequency cross-spectra from a pair of large Michelson interferometers

Aaron S. Chou·Richard Gustafson·Craig Hogan·Brittany Kamai·Ohkyung Kwon·Robert Lanza·Lee McCuller·Stephan S. Meyer·Jonathan Richardson·Chris Stoughton·Raymond Tomlin·Samuel Waldman·Rainer Weiss
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Abstract

Measurements are reported of the cross-correlation of spectra of differential position signals from the Fermilab Holometer, a pair of co-located 39 m long, high power Michelson interferometers with flat, broadband frequency response in the MHz range. The instrument obtains sensitivity to high frequency correlated signals far exceeding any previous measurement in a broad frequency band extending beyond the 3.8 MHz inverse light crossing time of the apparatus. The dominant but uncorrelated shot noise is averaged down over $2\times 10^8$ independent spectral measurements with 381 Hz frequency resolution to obtain $2.1\times 10^{-20} \ \mathrm{m}/\sqrt{\mathrm{Hz}}$ sensitivity to stationary signals. For signal bandwidths $\Delta f > 11$ kHz, the sensitivity to strain $h$ or shear power spectral density of classical or exotic origin surpasses a milestone $PSD_{\delta h} < t_p$ where $t_p= 5.39\times 10^{-44}/\mathrm{Hz}$ is the Planck time.

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Aaron S. Chou, Richard Gustafson, Craig Hogan, Brittany Kamai, Ohkyung Kwon, Robert Lanza, Lee McCuller, Stephan S. Meyer, Jonathan Richardson, Chris Stoughton, Raymond Tomlin, Samuel Waldman, Rainer Weiss. 2015-12-03. First measurements of high frequency cross-spectra from a pair of large Michelson interferometers. https://doi.org/10.1103/physrevlett.117.111102

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