Enhancement of mechanical Q factors by optical trapping

K. K. Ni, R. Norte, D. J. Wilson, J. D. Hood, D. E. Chang, O. Painter, H. J. Kimble

Research output: Contribution to journalArticlepeer-review

50 Scopus citations


The quality factor of a mechanical resonator is an important figure of merit for various sensing applications and for observing quantum behavior. Here, we demonstrate a technique to push the quality factor of a micromechanical resonator beyond conventional material and fabrication limits by using an optical field to stiffen or trap a particular motional mode. Optical forces increase the oscillation frequency by storing most of the mechanical energy in a nearly lossless optical potential, thereby strongly diluting the effect of material dissipation. By placing a 130 nm thick SiO 2 pendulum in an optical standing wave, we achieve an increase in the pendulum center-of-mass frequency from 6.2 to 145 kHz. The corresponding quality factor increases 50-fold from its intrinsic value to a final value of Q=5.8(1.1)×105, representing more than an order of magnitude improvement over the conventional limits of SiO 2 for this geometry. Our technique may enable new opportunities for mechanical sensing and facilitate observations of quantum behavior in this class of mechanical systems.

Original languageEnglish (US)
Article number214302
JournalPhysical review letters
Issue number21
StatePublished - May 21 2012
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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