Classical Pendulum Feels Quantum Back-Action

  • Nobuyuki¬†Matsumoto

Part of the Springer Theses book series (Springer Theses)

Table of contents

  1. Front Matter
    Pages i-xii
  2. Nobuyuki Matsumoto
    Pages 1-11
  3. Nobuyuki Matsumoto
    Pages 13-35
  4. Nobuyuki Matsumoto
    Pages 37-49
  5. Nobuyuki Matsumoto
    Pages 51-59
  6. Nobuyuki Matsumoto
    Pages 61-79
  7. Nobuyuki Matsumoto
    Pages 81-92
  8. Nobuyuki Matsumoto
    Pages 93-96
  9. Nobuyuki Matsumoto
    Pages 97-98
  10. Back Matter
    Pages 99-103

About this book


In this thesis, ultimate sensitive measurement for weak force imposed on a suspended mirror is performed with the help of a laser and an optical cavity for the development of gravitational-wave detectors. According to the Heisenberg uncertainty principle, such measurements are subject to a fundamental noise called quantum noise, which arises from the quantum nature of a probe (light) and a measured object (mirror). One of the sources of quantum noise is the quantum back-action, which arises from the vacuum fluctuation of the light. It sways the mirror via the momentum transferred to the mirror upon its reflection for the measurement. The author discusses a fundamental trade-off between sensitivity and stability in the macroscopic system, and suggests using a triangular cavity that can avoid this trade-off. The development of an optical triangular cavity is described and its characterization of the optomechanical effect in the triangular cavity is demonstrated. As a result, for the first time in the world the quantum back-action imposed on the 5-mg suspended mirror is significantly evaluated. This work contributes to overcoming the standard quantum limit in the future.


Double Optical Spring Effect Gravitational Dilution Interferometric Gravitational-wave Detectors Optical Torsional Spring Effect Optomechanics Radiation Pressure Shot Noise Siddles-Sigg Instability Triangular Cavity

Authors and affiliations

  • Nobuyuki¬†Matsumoto
    • 1
  1. 1.Department of Physics, Graduate School of Science,The University of TokyoTokyoJapan

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