6,481 research outputs found
Injection locking of optomechanical oscillators via acoustic waves
Injection locking is a powerful technique for synchronization of oscillator
networks and controlling the phase and frequency of individual oscillators
using similar or other types of oscillators. Here, we present the first
demonstration of injection locking of a radiation-pressure driven
optomechanical oscillator (OMO) via acoustic waves. As opposed to previously
reported techniques (based on pump modulation or direct application of a
modulated electrostatic force), injection locking of OMO via acoustic waves
does not require optical power modulation or physical contact with the OMO and
it can easily be implemented on various platforms. Using this approach we have
locked the phase and frequency of two distinct modes of a microtoroidal silica
OMO to a piezoelectric transducer (PZT). We have characterized the behavior of
the injection locked OMO with three acoustic excitation configurations and
showed that even without proper acoustic impedance matching the OMO can be
locked to the PZT and tuned over 17 kHz with only -30 dBm of RF power fed to
the PZT. The high efficiency, simplicity and scalability of the proposed
approach paves the road toward a new class of photonic systems that rely on
synchronization of several OMOs to a single or multiple RF oscillators with
applications in optical communication, metrology and sensing. Beyond its
practical applications, injection locking via acoustic waves can be used in
fundamental studies in quantum optomechanics where thermal and optical
isolation of the OMO are critical
Stabilized lasers for advanced gravitational wave detectors
Second generation gravitational wave detectors require high power lasers with more than 100 W of output power and with very low temporal and spatial fluctuations. To achieve the demanding stability levels required, low noise techniques and adequate control actuators have to be part of the high power laser design. In addition feedback control and passive noise filtering is used to reduce the fluctuations in the so-called prestabilized laser system (PSL). In this paper, we discuss the design of a 200 W PSL which is under development for the Advanced LIGO gravitational wave detector and will present the first results. The PSL noise requirements for advanced gravitational wave detectors will be discussed in general and the stabilization scheme proposed for the Advanced LIGO PSL will be described
Measuring the universal synchronization properties of coupled oscillators across the Hopf instability
When a driven oscillator loses phase-locking to a master oscillator via a
Hopf bifurcation, it enters a bounded-phase regime in which its average
frequency is still equal to the master frequency, but its phase displays
temporal oscillations. Here we characterize these two synchronization regimes
in a laser experiment, by measuring the spectrum of the phase fluctuations
across the bifurcation. We find experimentally, and confirm numerically, that
the low frequency phase noise of the driven oscillator is strongly suppressed
in both regimes in the same way. Thus the long-term phase stability of the
master oscillator is transferred to the driven one, even in the absence of
phase-locking. The numerical study of a generic, minimal model suggests that
such behavior is universal for any periodically driven oscillator near a Hopf
bifurcation point.Comment: 5 pages, 5 figure
The GEO 600 laser system
Interferometric gravitational wave detectors require high optical power, single frequency lasers with very good beam quality and high amplitude and frequency stability as well as high long-term reliability as input light source. For GEO 600 a laser system with these properties is realized by a stable planar, longitudinally pumped 12 W Nd:YAG rod laser which is injection-locked to a monolithic 800 mW Nd:YAG non-planar ring oscillator. Frequency control signals from the mode cleaners are fed to the actuators of the non-planar ring oscillator which determines the frequency stability of the system. The system power stabilization acts on the slave laser pump diodes which have the largest influence on the output power. In order to gain more output power, a combined Nd:YAGNd:YVO4 system is scaled to more than 22 W
Injection locking of an electro-optomechanical device
The techniques of cavity optomechanics have enabled significant achievements
in precision sensing, including the detection of gravitational waves and the
cooling of mechanical systems to their quantum ground state. Recently, the
inherent non-linearity in the optomechanical interaction has been harnessed to
explore synchronization effects, including the spontaneous locking of an
oscillator to a reference injection signal delivered via the optical field.
Here, we present the first demonstration of a radiation-pressure driven
optomechanical system locking to an inertial drive, with actuation provided by
an integrated electrical interface. We use the injection signal to suppress
drift in the optomechanical oscillation frequency, strongly reducing phase
noise by over 55 dBc/Hz at 2 Hz offset. We further employ the injection tone to
tune the oscillation frequency by more than 2 million times its narrowed
linewidth. In addition, we uncover previously unreported synchronization
dynamics, enabled by the independence of the inertial drive from the optical
drive field. Finally, we show that our approach may enable control of the
optomechanical gain competition between different mechanical modes of a single
resonator. The electrical interface allows enhanced scalability for future
applications involving arrays of injection-locked precision sensors.Comment: Main text: 10 pages, 7 figures. Supplementary Information: 5 pages, 4
figure
Frequency-locked chaotic opto-RF oscillator
A driven opto-RF oscillator, consisting of a dual-frequency laser (DFL)
submitted to frequency-shifted feedback, is studied experimentally and
numerically in a chaotic regime. Precise control of the reinjection strength
and detuning permits to isolate a parameter region of bounded-phase chaos,
where the opto-RF oscillator is frequency-locked to the master oscillator, in
spite of chaotic phase and intensity oscillations. Robust experimental evidence
of this synchronization regime is found and phase noise spectra allows to
compare phase-locking and bounded-phase chaos regimes. In particular, it is
found that the long-term phase stability of the master oscillator is well
transferred to the opto-RF oscillator even in the chaotic regime
Stabilized High Power Laser for Advanced Gravitational Wave Detectors
Second generation gravitational wave detectors require high power lasers with several 100W of output power and with very low temporal and spatial fluctuations. In this paper we discuss possible setups to achieve high laser power and describe a 200W prestabilized laser system (PSL). The PSL noise requirements for advanced gravitational wave detectors will be discussed in general and the stabilization scheme proposed for the Advanced LIGO PSL will be described. Special emphasis will be given to the most demanding power stabilization requiremets and new results (RIN ≤ 4×10-9/surdHz) will be presented
Coherent control of broadband vacuum squeezing
We present the observation of optical fields carrying squeezed vacuum states
at sideband frequencies from 10Hz to above 35MHz. The field was generated with
type-I optical parametric oscillation below threshold at 1064nm. A coherent,
unbalanced classical modulation field at 40MHz enabled the generation of error
signals for stable phase control of the squeezed vacuum field with respect to a
strong local oscillator. Broadband squeezing of approximately -4dB was measured
with balanced homodyne detection. The spectrum of the squeezed field allows a
quantum noise reduction of ground-based gravitational wave detectors over their
full detection band, regardless of whether homodyne readout or radio-frequency
heterodyne readout is used.Comment: 9 pages, 8 figure
Magneto Acoustic Spin Hall Oscillators
This paper introduces a novel oscillator that combines the tunability of spin
Hall-driven nano oscillators with the high quality factor (Q) of high overtone
bulk acoustic wave resonators (HBAR), integrating both reference and tunable
oscillators on the same chip with CMOS. In such magneto acoustic spin Hall
(MASH) oscillators, voltage oscillations across the magnetic tunnel junction
(MTJ) that arise from a spin-orbit torque (SOT) are shaped by the transmission
response of the HBAR that acts as a multiple peak-bandpass filter and a delay
element due to its large time constant, providing delayed feedback. The
filtered voltage oscillations can be fed back to the MTJ via a) strain, b)
current, or c) magnetic field. We develop a SPICE-based circuit model by
combining experimentally benchmarked models including the stochastic
Landau-Lifshitz-Gilbert (sLLG) equation for magnetization dynamics and the
Butterworth Van Dyke (BVD) circuit for the HBAR. Using the self-consistent
model, we project up to 50X enhancement in the oscillator linewidth with
Q reaching up to 52825 at 3 GHz, while preserving the tunability by locking the
STNO to the nearest high Q peak of the HBAR. We expect that our results will
inspire MEMS-based solutions to spintronic devices by combining attractive
features of both fields for a variety of applications
An Optomechanical Oscillator on a Silicon Chip
The recent observation on radiation-pressure-driven self-sustained oscillation in high-Q optical microresonators has created new possibilities for development of photonic devices that benefit from unique functionalities offered by these “optomechanical oscillators” (OMOs). Here, we review the physics, fundamental characteristics, and potential applications of OMOs using the silica microtoroidal OMO as an example
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