Topic
Self-oscillation
About: Self-oscillation is a research topic. Over the lifetime, 159 publications have been published within this topic receiving 2067 citations. The topic is also known as: self-induced oscillation & self-excited oscillation.
Papers published on a yearly basis
Papers
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TL;DR: In a self-oscillator, the driving force is controlled by the oscillation itself so that it acts in phase with the velocity, causing a negative damping that feeds energy into the vibration: no external rate needs to be adjusted to the resonant frequency.
Abstract: Physicists are very familiar with forced and parametric resonance, but usually not with self-oscillation, a property of certain dynamical systems that gives rise to a great variety of vibrations, both useful and destructive In a self-oscillator, the driving force is controlled by the oscillation itself so that it acts in phase with the velocity, causing a negative damping that feeds energy into the vibration: no external rate needs to be adjusted to the resonant frequency The famous collapse of the Tacoma Narrows bridge in 1940, often attributed by introductory physics texts to forced resonance, was actually a self-oscillation, as was the swaying of the London Millennium Footbridge in 2000 Clocks are self-oscillators, as are bowed and wind musical instruments The heart is a "relaxation oscillator," ie, a non-sinusoidal self-oscillator whose period is determined by sudden, nonlinear switching at thresholds We review the general criterion that determines whether a linear system can self-oscillate We then describe the limiting cycles of the simplest nonlinear self-oscillators, as well as the ability of two or more coupled self-oscillators to become spontaneously synchronized ("entrained") We characterize the operation of motors as self-oscillation and prove a theorem about their limit efficiency, of which Carnot's theorem for heat engines appears as a special case We briefly discuss how self-oscillation applies to servomechanisms, Cepheid variable stars, lasers, and the macroeconomic business cycle, among other applications Our emphasis throughout is on the energetics of self-oscillation, often neglected by the literature on nonlinear dynamical systems
388 citations
TL;DR: In this article, it is shown that two light beams interacting in a third-order nonlinear medium undergo transition from a stationary to periodic and chaotic states, as their intensities are increased.
Abstract: It is shown that two light beams interacting in a third-order nonlinear medium undergo transition from a stationary to periodic and chaotic states, as their intensities are increased. A threshold for the onset of instabilities is calculated and verified by computer simulations. It is therefore proved that external feedback is not necessary for self-oscillations in nonlinear optical systems.
125 citations
TL;DR: The corresponding damping rate is lower than the one obtained from the line shape of the resonance (without pumping), supporting the recently reported scenario that describes damping in nanotube resonators by a nonlinear force.
Abstract: A hallmark of mechanical resonators made from a single nanotube is that the resonance frequency can be widely tuned. Here, we take advantage of this property to realize parametric amplification and self-oscillation. The gain of the parametric amplification can be as high as 18.2 dB and tends to saturate at high parametric pumping due to nonlinear damping. These measurements allow us to determine the coefficient of the linear damping force. The corresponding damping rate is lower than the one obtained from the line shape of the resonance (without pumping), supporting the recently reported scenario that describes damping in nanotube resonators by a nonlinear force. The possibility to combine nanotube resonant mechanics and parametric amplification holds promise for future ultralow force sensing experiments.
123 citations
TL;DR: In this article, the authors present the theory of a Josephson parametric amplifier employing two-pump sources, and analyze the operation of the device, taking into account the feedback introduced by the reaction of the signal and noise on the pump power.
Abstract: We present the theory of a Josephson parametric amplifier employing two-pump sources. Our calculations are based on input-output theory, and can easily be generalized to any coupled system involving parametric interactions. We analyze the operation of the device, taking into account the feedback introduced by the reaction of the signal and noise on the pump power, and in this framework, compute the response functions of interest--signal and idler gains, internal gain of the amplifier, and self-oscillation signal amplitude. To account for this back action between signal and pump, we adopt a mean-field approach and self-consistently explore the boundary between amplification and self-oscillation. The coincidence of bifurcation and self-oscillation thresholds reveals that the origin of coherent emission of the amplifier lies in the multiwave mixing of the noise components. Incorporation of the back action leads the system to exhibit hysteresis, dependent on parameters such as temperature and detuning from resonance. Our analysis also shows that the resonance condition itself changes in the presence of back action and this can be understood in terms of the change in plasma frequency of the junction. The potential of the double-pump amplifier for quantum-limited measurements and as a squeezer is also discussed.
103 citations
TL;DR: In this article, the phase conjugated wave reflected from a self-pumped photorefractive BaTiO3 crystal has been observed to be increased by providing optical feedback of the light scattered during grating formation.
82 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 2 |
| 2024 | 5 |
| 2023 | 2 |
| 2022 | 11 |
| 2021 | 6 |
| 2020 | 3 |