Optical read out and feedback cooling of a nanostring optomechanical cavity
Optical measurement of the motion of a 940 kHz mechanical resonance of a silicon nitride nanostring resonator is demonstrated with a read out noise imprecision reaching 37 dB below that of the resonator's zero-point fluctuations. Via intensity modulation of the optical probe laser, radiation pr...
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Main Authors | , , |
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Format | Journal Article |
Language | English |
Published |
03.06.2015
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Subjects | |
Online Access | Get full text |
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Summary: | Optical measurement of the motion of a 940 kHz mechanical resonance of a
silicon nitride nanostring resonator is demonstrated with a read out noise
imprecision reaching 37 dB below that of the resonator's zero-point
fluctuations. Via intensity modulation of the optical probe laser, radiation
pressure feedback is used to cool and damp the mechanical mode from an initial
room temperature occupancy of $\bar{n}_{b} = 6.5 \times 10^6$ ($T_{b}=295$K)
down to a phonon occupation of $\langle n \rangle = 66 \pm 10$, representing a
mode temperature of $T_{m} \approx 3$mK. The five decades of cooling is enabled
by the system's large single-photon cooperativity $(C_{1} = 4)$ and high
quantum efficiency of optical motion detection ($\eta_{t} = 0.27$). |
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DOI: | 10.48550/arxiv.1506.01249 |