167 research outputs found
Opto-Mechanics of deformable Fabry-Perot Cavities
We investigated the opto-mechanical properties of a Fabry-Perot cavity with a
mirror mounted on a spring. Such a structure allows the cavity length to change
elastically under the effect of light induced forces. This opto-mechanical
coupling is exploited to control the amplitude of mechanical fluctuation of the
mirror. We present a model developed in the classical limit and discuss data
obtained in the particular case for which photo-thermal forces are dominant.Comment: 26 pages, 7 figure
Opto-Mechanics of deformable Fabry-Perot Cavities
We investigated the opto-mechanical properties of a Fabry-Perot cavity with a
mirror mounted on a spring. Such a structure allows the cavity length to change
elastically under the effect of light induced forces. This opto-mechanical
coupling is exploited to control the amplitude of mechanical fluctuation of the
mirror. We present a model developed in the classical limit and discuss data
obtained in the particular case for which photo-thermal forces are dominant.Comment: 26 pages, 7 figure
Self-induced oscillations in an optomechanical system
We have explored the nonlinear dynamics of an optomechanical system
consisting of an illuminated Fabry-Perot cavity, one of whose end-mirrors is
attached to a vibrating cantilever. Such a system can experience negative
light-induced damping and enter a regime of self-induced oscillations. We
present a systematic experimental and theoretical study of the ensuing
attractor diagram describing the nonlinear dynamics, in an experimental setup
where the oscillation amplitude becomes large, and the mirror motion is
influenced by several optical modes. A theory has been developed that yields
detailed quantitative agreement with experimental results. This includes the
observation of a regime where two mechanical modes of the cantilever are
excited simultaneously.Comment: 4.5 pages, 3 figures (v2: corrected few typos
Photoelastic coupling in gallium arsenide optomechanical disk resonators
We analyze the magnitude of the radiation pressure and electrostrictive
stresses exerted by light confined inside GaAs semiconductor WGM optomechanical
disk resonators, through analytical and numerical means, and find the
electrostrictive force to be of prime importance. We investigate the geometric
and photoelastic optomechanical coupling resulting respectively from the
deformation of the disk boundary and from the strain-induced refractive index
changes in the material, for various mechanical modes of the disks.
Photoelastic optomechanical coupling is shown to be a predominant coupling
mechanism for certain disk dimensions and mechanical modes, leading to total
coupling g and g reaching respectively 3 THz/nm and 4 MHz. Finally,
we point towards ways to maximize the photoelastic coupling in GaAs disk
resonators, and we provide some upper bounds for its value in various
geometries
High frequency GaAs nano-optomechanical disk resonator
Optomechanical coupling between a mechanical oscillator and light trapped in
a cavity increases when the coupling takes place in a reduced volume. Here we
demonstrate a GaAs semiconductor optomechanical disk system where both optical
and mechanical energy can be confined in a sub-micron scale interaction volume.
We observe giant optomechanical coupling rate up to 100 GHz/nm involving
picogram mass mechanical modes with frequency between 100 MHz and 1 GHz. The
mechanical modes are singled-out measuring their dispersion as a function of
disk geometry. Their Brownian motion is optically resolved with a sensitivity
of 10^(-17)m/sqrt(Hz) at room temperature and pressure, approaching the quantum
limit imprecision.Comment: 7 pages, 3 figure
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