Quantum Radiation Pressure Noise Reduction and Evasion

Abstract

The measurement of quantum radiation pressure noise in Chap. 6 creates the opportunity to study various techniques for reducing QRPN. This chapter describes two experiments in which we reduce the amount of QRPN. The first experiment demonstrates the elimination of QRPN from the measurement, or QRPN evasion, by modifying how the light from the cavity is detected. The second experiment modifies or squeezes the light that is injected into the optomechanical cavity by altering the quantum mechanical fluctuations in the amplitude and phase quadratures of the light. The motivation for doing each of these experiments stems from the fact that they represent two methods that have been proposed for reducing quantum radiation pressure noise in gravitational wave detectors (Kimble et al. in Phys Rev D 65:022002, (2001) [1]), with squeezing currently being installed in the LIGO interferometers for reducing the shot noise during the third observing run and beyond (Tse et al. in Phys Rev Lett 123:231107, (2019) [2]). Results from this chapter can be found in Cripe et al. (Quantum back action cancellation in the audio band, (2018), [3]) and Yap et al. (Nature Photonics 14:19–23, (2020) [4]).