We present the measurement of squeezed light generation using an engineered optomechanical system fabricated from a silicon microchip and composed of a micromechanical resonator coupled to a nanophotonic cavity. Laser light is used to measure the fluctuations in the position of the mechanical resonator at a measurement rate comparable to the free dynamics of the mechanical resonator, and greater than its thermal decoherence rate. By approaching the strong continuous measurement regime we observe, through homodyne detection, non-trivial modifications of the reflected light's vacuum fluctuation spectrum. In spite of the mechanical resonator's highly excited thermal state (10,000 phonons), we observe squeezing at the level of 4.5±0.5 below that of shot-noise over a few MHz bandwidth around the mechanical resonance frequency of 28 MHz. This squeezing is interpreted as an unambiguous quantum signature of radiation pressure shot-noise.
@article{arxiv.1302.6179,
title = {Squeezing of light via reflection from a silicon micromechanical resonator},
author = {Amir H. Safavi-Naeini and Simon Groeblacher and Jeff T. Hill and Jasper Chan and Markus Aspelmeyer and Oskar Painter},
journal= {arXiv preprint arXiv:1302.6179},
year = {2013}
}