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threshold-of-instability
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Effects of optical parametric amplifier pump phase noise on the cooling of optomechanical resonators
, Article Journal of the Optical Society of America B: Optical Physics ; Volume 30, Issue 7 , 2013 , Pages 1898-1904 ; 07403224 (ISSN) ; Bahrampour, A. R ; Sharif Univeristy of Technology
2013
Abstract
In this paper, the effect of parametric amplifier pump phase noise on the cooling of a micromirror in an optomechanical system with an optical parametric amplifier inside the optical cavity is investigated theoretically. It has been demonstrated that the photon number distribution of a parametric amplifier near the threshold of instability leads to improved cooling of the micromirror. But due to the presence of the parametric amplifier, there is a resonance detuning frequency for transferring noise energy to the potential and kinetic energy fluctuations of the mirror which causes the mirror mechanical oscillation mode temperature to increase. In low quality factor cavities, this effect...
Investigation of the small-scale effects on the three-dimensional flexural vibration characteristics of a basic model for micro-engines
, Article Acta Mechanica ; Volume 226, Issue 9 , September , 2015 , Pages 3085-3096 ; 00015970 (ISSN) ; Asghari, M ; Sharif University of Technology
Springer-Verlag Wien
2015
Abstract
The coupled three-dimensional flexural vibrations of a micro-rotating shaft–disk system, as a basic model for micro-engines, are investigated in this paper by considering small-scale effects utilizing the modified couple stress theory. Governing equations of motion are derived by the use of Hamilton’s principle. Then, implementing the Galerkin approach, an infinite set of ordinary differential equations is obtained for the system. With truncated two-term equations, expressions for the first two natural frequencies are written, and for the two corresponding modes, the maximum rotational speed up to which the system will be stable is analytically determined. Parametric studies on the results...