Showing papers on "Parametric oscillator published in 1999"
TL;DR: In this article, a monolithic high-Q oscillator, fabricated via a combined CMOS plus surface micromachining technology, is described, for which the oscillation frequency is controlled by a polysilicon micromechanical resonator with the intent of achieving high stability.
Abstract: A completely monolithic high-Q oscillator, fabricated via a combined CMOS plus surface micromachining technology, is described, for which the oscillation frequency is controlled by a polysilicon micromechanical resonator with the intent of achieving high stability. The operation and performance of micromechanical resonators are modeled, with emphasis on circuit and noise modeling of multiport resonators. A series resonant oscillator design is discussed that utilizes a unique, gain-controllable transresistance sustaining amplifier. We show that in the absence of an automatic level control loop, the closed-loop, steady-state oscillation amplitude of this oscillator depends strongly upon the dc-bias voltage applied to the capacitively driven and sensed /spl mu/resonator. Although the high-Q of the micromechanical resonator does contribute to improved oscillator stability, its limited power-handling ability outweighs the Q benefits and prevents this oscillator from achieving the high short-term stability normally expected of high-Q oscillators.
431 citations
TL;DR: In this paper, the dynamic response of an axially accelerating, elastic, tensioned beam is investigated, where the time-dependent velocity is assumed to vary harmonically about a constant mean velocity.
229 citations
TL;DR: In this article, it was shown that non-selfadjoint harmonic and anharmonic oscillator operators have nontrivial pseudospectra, and that the computation of highenergy resonances by the dilation analyticity of the oscillator operator can be carried out in a non-uniform manner.
Abstract: We prove that nonselfadjoint harmonic and anharmonic oscillator operators have nontrivial pseudospectra. As a consequence, the computation of highenergy resonances by the dilation analyticity techn...
162 citations
TL;DR: In this article, an exact analytic solution to the neutrino evolution equation in matter with a periodic step-function density profile was presented, and parametric resonance of neutrinos oscillations that can occur in such a system was discussed in detail.
149 citations
TL;DR: In this paper, an example of exact parametric resonance in an extended system ruled by nonlinear partial differential equations of nonlinear Schrodinger type is studied, and the results have applicability in recent experiments in Bose-Einstein condensation and to classical problems in nonlinear optics.
Abstract: We study an example of exact parametric resonance in an extended system ruled by nonlinear partial differential equations of nonlinear Schr\"odinger type. It is also conjectured how related models not exactly solvable should behave in the same way. The results have applicability in recent experiments in Bose-Einstein condensation and to classical problems in nonlinear optics.
135 citations
TL;DR: Tuning over almost the entire bandwidth of Er-doped-fiber amplifiers is demonstrated, and one could construct a similar device that operates near the 1310-nm zero-dispersion wavelength of standard telecommunication fiber.
Abstract: A tunable fiber optic parametric oscillator includes a nonlinear optical loop mirror or fiber Sagnac interferometer NFSI with a dispersion shifted fiber portion. The oscillator is synchronously pumped to amplify a signal wave, while reflecting the depleted pump pulse back towards the pump. The amplified signal wave and simultaneously generated idler waves are directed to a spectral filter. The spectral filter may be a diffraction grating, a Faraday mirror or other optical filter that is tunable to change the signal wavelength that is reflected back to the NFSI. The fiber optic parametric oscillator is tunable over substantially the entire gain bandwidth and is insensitive to the polarization of the pump pulses. The fiber optic parametric oscillator may be used as a tunable source of short pulses for high speed optical communication systems. The fiber optic parametric oscillator may also be used for synchronization and clock recovery.
106 citations
79 citations
TL;DR: A novel broadband optical frequency comb generator consisting of a parametric oscillator with an intracavity electro-optic phase modulator, which results in a dispersion-limited comb that spans 20 nm (5.3 THz).
Abstract: We introduce a novel broadband optical frequency comb generator consisting of a parametric oscillator with an intracavity electro-optic phase modulator. The parametric oscillator is pumped by 532-nm light and produces near-degenerate signal and idler fields. The modulator generates a comb structure about both the signal and the idler. Coupling between the two families of modes results in a dispersion-limited comb that spans 20 nm (5.3 THz). A signal-to-noise ratio of >30 dB in a 300-kHz bandwidth is observed in the beat frequency between individual comb elements and a reference laser.
72 citations
23 Aug 1999
TL;DR: In this article, a CMOS relaxation oscillator is presented, which has only one tail current source unlike the emitter coupled multivibrator, which enhances the operating speed without increasing the power consumption.
Abstract: In this paper, a CMOS relaxation oscillator is presented. The proposed oscillator has only one tail current source unlike the emitter coupled multivibrator. All the tail current flows through the timing capacitor and thus the charging slope of the timing capacitor is doubled. This enhances the operating speed without increasing the power consumption. The oscillator is fabricated in a standard 0.8 /spl mu/m CMOS process. The maximum operating frequency is 923 MHz at a 3.3 V single supply, while the oscillator draws 6 mA.
67 citations
TL;DR: Generation of bright sub-Poissonian light is demonstrated by means of parametric deamplification in a phase-sensitive fiber amplifier that is based on a balanced nonlinear Sagnac interferometer and a simplified semiclassical theory of quantum-noise suppression is found to be in good agreement with the experimental results.
Abstract: We experimentally demonstrate generation of bright sub-Poissonian light by means of parametric deamplification in a phase-sensitive fiber amplifier that is based on a balanced nonlinear Sagnac interferometer. On direct detection, the photocurrent noise falls below the shot-noise limit by 0.6±0.2 dB (1.4 dB when corrected for detection losses). To observe the noise reduction we employed a scheme that used two orthogonally polarized pulses to cancel the noise that arises from the predominantly polarized guided-acoustic-wave Brillouin scattering in the fiber. We also present a simplified semiclassical theory of quantum-noise suppression by this amplifier, which is found to be in good agreement with the experimental results.
64 citations
TL;DR: In this article, a control law based on cubic velocity feedback is proposed to suppress the vibrations of the first mode of a cantilever beam when subjected to a principal parametric resonance.
TL;DR: In this article, the nonlinear planar response of a hinged-clamped beam to a principal parametric resonance of either its first or second mode or a combination parametric Resonance of the additive type of its first two modes is investigated.
Abstract: The nonlinear planar response of a hinged-clamped beam to a principal parametric resonance of either its first or second mode or a combination parametric resonance of the additive type of its first two modes is investigated. The analysis accounts for mid-plane stretching, a static axial load, a restraining spring at one end, and modal damping. The natural frequency of the second mode is approximately three times the natural frequency of the first mode for a range of static axial loads, resulting in a three-to-one internal resonance. The method of multiple scales is used to attack directly the governing nonlinear integral-partial-differential equation and associated boundary conditions and derive three sets of four first-order nonlinear ordinary-differential equations describing the modulation of the amplitudes and phases of the first two modes in the cases of (a) principal parametric resonance of either the first or the second mode, and (b) a combination parametric resonance of the additive type of these modes. Periodic motions and periodically and chaotically modulated motions of the beam are determined by investigating the equilibrium and dynamic solutions of the modulation equations. For the case of principal parametric resonance of the first mode or combination parametric resonance of the additive type, trivial and two-mode solutions are possible, whereas for the case of parametric resonance of the second mode, trivial, single, and two-mode solutions are possible. The trivial and two-mode equilibrium solutions of the modulation equations may undergo either a supercritical or a subcritical Hopf bifurcation, depending on the magnitude of the axial load. For some excitation parameters, we found complex responses including period-doubling bifurcations and blue-sky catastrophes.
TL;DR: In this paper, a synchronously pumped femtosecond optical parametric oscillator based on periodically poled LiNbO3 was proposed for tunable in the mid infrared.
Abstract: We describe a synchronously pumped femtosecond optical parametric oscillator based on periodically poled LiNbO3 that is broadly tunable in the mid infrared. A transmission window of periodically poled lithium niobate beyond the conventionally accepted infrared absorption edge of 5.4 µm has been exploited to produce idler pulses that are tunable across a wavelength range of 4 µm, with milliwatt-level output powers at wavelengths as long as 6.8 µm. We also present experimental tuning results that are in good agreement with the theoretical phase matching predicted from published infrared-corrected Sellmeier equations for LiNbO3.
TL;DR: A high-efficiency ZnGeP(2) optical parametric oscillator (OPO) pumped by another KTP OPO in a multimode-pumped tandem OPO configuration with maximum optical-to-optical and slope efficiencies was 32% and 42.5%, respectively.
Abstract: We demonstrate a high-efficiency ZnGeP2 optical
parametric oscillator (OPO) pumped by another KTP OPO in a
multimode-pumped tandem OPO configuration. The maximum
optical-to-optical and slope efficiencies were 32% and 42.5%,
respectively. Our setup also provides tunable multiband radiation
in the 2.03–2.32-µm range and the 2.9–6.2-µm range
simultaneously.
TL;DR: In this paper, the stability of the trivial limit cycle of general summation parametric resonance was investigated using the Routh-Hurwitz criterion and closed-form expressions for the stability boundaries were derived.
Abstract: The amplitude and existence conditions of nontrivial limit cycles are derived in the companion paper by the use of the method of multiple scales. In this paper, the stability for parametrically excited viscoelastic moving belts is studied. Stability boundaries of the trivial limit cycle for general summation parametric resonance are obtained. The Routh-Hurwitz criterion is used to investigate the stability of nontrivial limit cycles. Closed-form expressions are found for the stability of nontrivial limit cycles of general summation parametric resonance. It is shown that the first limit cycle is always stable while the second limit cycle is always unstable for the viscoelastic moving belts. The effects of viscoelastic parameters, excitation frequencies, excitation amplitudes, and axial moving speeds on stability boundaries are discussed.
TL;DR: In this article, the first singly resonant cw optical parametric oscillator (SRO) that is directly pumped by a diode laser was presented. But the SRO was not designed to be used in a single-input single-output (SISO) system.
Abstract: We report on what is believed to be the first singly resonant cw optical parametric oscillator (SRO) that is directly pumped by a diode laser. The SRO consists of a 38-mm-long periodically poled LiNbO3 crystal in a four-mirror signal-resonant ring cavity. Pumped by 2.5 W of 925-nm diode-laser radiation, the SRO generates 480 mW of single-frequency idler radiation at 2.1 µm. The wavelengths of the signal and the idler output are tuned in the ranges of 1.55 to 1.70 µm and 2.03 to 2.29 µm, respectively, by tuning the wavelength of the diode laser from 924.0 to 925.4 nm.
TL;DR: In this paper, the stability of the interface separating immiscible incompressible fluids of different densities and viscosities is considered in the case of fluids filling a cavity which performs horizontal harmonic oscillations.
Abstract: The stability of the interface separating two immiscible incompressible fluids of different densities and viscosities is considered in the case of fluids filling a cavity which performs horizontal harmonic oscillations. There exists a simple basic state which corresponds to the unperturbed interface and plane-parallel unsteady counter flows; the properties of this state are examined. A linear stability problem for the interface is formulated and solved for both (a) inviscid and (b) viscous fluids. A transformation is found which reduces the linear stability problem under the inviscid approximation to the Mathieu equation. The parametric resonant regions of instability associated with the intensification of capillary-gravity waves at the interface are examined and the results are compared to those found in the viscous case in a fully numerical investigation.
TL;DR: In this article, the authors studied the parametric excitation of an elevated water tower experiencing sloshing hydro-dynamic impact using the multiple scales method and modeled the impact loads based on a phenomenological representation in the form of a power function with a higher exponent.
Abstract: The parametric excitation of an elevated water tower experiencing sloshing hydro-dynamic impact is studied using the multiple scales method. The liquid sloshing mass is replaced by a mechanical model in the form of a simple pendulum experiencing impacts with the tank walls. The impact loads are modeled based on a phenomenological representation in the form of a power function with a higher exponent. In this case the system equations of motion include impact nonlinearities (selected to be of fifth power) and cubic structural geometric nonlinearities. When the first mode is parametrically excited the system exhibits hard nonlinear behavior and the impact loading reduced the response amplitude. On the other hand, when the second mode is parametrically excited, the impact loading results in complex response behavior characterized by multiple steady state solutions, where the response switches from soft to hard nonlinear characteristics. Under combined parametric resonance, the system possesses a single steady-state response in the absence and in the presence of impact. However, the system behaves like a soft system in the absence of impact and like a hard system in the presence of impact.
TL;DR: In this paper, the design and operation of a pulsed quasi-phase-matched periodically poled lithium niobate optical parametric oscillator in the grazing incidence configuration are described.
Abstract: The design and operation of a pulsed quasi-phase-matched periodically poled lithium niobate optical parametric oscillator in the grazing incidence configuration are described. A narrow bandwidth of 0.3 cm-1 is demonstrated over most of the full tuning range of the device. Broad and rapid scanning has been achieved by rotation of a single mirror. Long-term stable operation and a pump-to-signal power efficiency of 46% are shown to be possible. Methods to improve the bandwidth are discussed.
TL;DR: In this article, the instability of fluctuations in an oscillating scalar field which obeys the sine-Gordon equation is considered, and simple closed-form analytic solutions describing the parametric resonance of the axion fluctuations are presented.
TL;DR: In this paper, the adiabatic density perturbation in the oscillating inflation was studied and it was shown that the metric perturbations play a crucial role in the evolution of scalar field perturbants.
Abstract: We study the adiabatic density perturbation in the {\it oscillating inflation}, proposed by Damour and Mukhanov. The recent study of the cosmological perturbation during reheating shows that the adiabatic fluctuation behaves like as the perfect fluid and no significant amplification occurs on super-horizon scales. In the oscillating inflation, however, the accelerated expansion takes place during the oscillating stage and there might be a possibility that the parametric amplification on small scales affects the adiabatic long-wavelength perturbation. We analytically show that the density perturbation neglecting the metric perturbation can be amplified by the parametric resonance and the instability band becomes very broad during the oscillating inflation. We examined this issue by solving the evolution equation for perturbation numerically. We found that the parametric resonance is strongly suppressed for the long wave modes comparable to the Hubble horizon. The result indicates that the metric perturbation plays a crucial role for the evolution of scalar field perturbation. Therefore, in the single field case, there would be no significant imprint of the oscillating inflation on the primordial spectrum of the adiabatic perturbation. However, it could be expected that the oscillating inflation in the multi-field system gives the enormous amplification on large scales, which may lead to the production of the primordial black holes.
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TL;DR: A package of simulation programs is developed suited for examining the phenomenon of paramagnetic resonance in a linear system, which simulates the parametric excitation of the rotary oscillations of a mechanical torsion-spring pendulum whose moment of inertia is subject to periodic variations.
Abstract: Computer simulation experiments are especially good tools for helping students understand basic principles of physics. In this a, I have developed a package of simulation programs called Physics of Oscillations. One of its programs is suited for examining the phenomenon of paramagnetic resonance in a linear system. The program simulates the parametric excitation of the rotary oscillations of a mechanical torsion-spring pendulum whose moment of inertia is subject to periodic variations. I discuss the conditions and characteristics of parametric resonance, including paramagnetic regeneration. Instructors and their students can also use the Physics of Oscillations package to explore other problems, such as ranges of frequencies within which parametric excitation is possible and stationary oscillations on the boundaries of these ranges. The simulation experiments complement the analytical study of the subject in a manner that is mutually reinforcing.
TL;DR: In this paper, a design method for an optimized high-efficiency harmonic loaded oscillator is presented, which predicts the performance of oscillators including output power, dc-RF conversion efficiency and dc-bias current shift during start-up transition.
Abstract: We present a design method for an optimized high-efficiency harmonic loaded oscillator. The proposed approach predicts the performance of oscillators including output power, dc-RF conversion efficiency, and dc-bias current shift during start-up transition. In this method, the performance of the oscillator can he optimized based on the performance analysis of the active device under the assumed operation conditions. The effects of fundamental and harmonic loading on output power and efficiency are investigated by the proposed approach. Two kinds of stability conditions are addressed for an oscillator initially biased at a low gate voltage. Using the proposed approach, we design an oscillator that has a high efficiency of 61% at 1.86 GHz with a very low bias voltage of 2.0 V.
TL;DR: In this article, the non-linear behavior of a slender beam carrying a lumped mass subjected to principal parametric base excitation is investigated, where the dimension of the beam-mass system and the position of the attached mass are so adjusted that the system exhibits 3 ǫ: 1 internal resonance.
Abstract: The non-linear behaviour of a slender beam carrying a lumped mass subjected to principal parametric base excitation is investigated. The dimension of the beam–mass system and the position of the attached mass are so adjusted that the system exhibits 3 : 1 internal resonance. Multi-mode discretization of the governing equation which retains the cubic non-linearities of geometrical and inertial type is carried out using Galerkin’s method. The method of multiple scales is used to reduce the second-order temporal differential equation to a set of first-order differential equations which is then solved numerically to obtain the steady-state response and the stability of the system. The linear first-order perturbation results show new zones of instability due to the presence of internal resonance. For low amplitude of excitation and damping Hopf bifurcations are observed in the trivial steady-state response. The multi-branched non-trivial response curves show turning point, pitch-fork and Hopf bifurcations. Cascade of period and torus doubling, crises as well as the Shilnikov mechanism for chaos are observed. This is the first natural physical system exhibiting a countable infinity of horseshoes in a neighbourhood of the homoclinic orbit.
TL;DR: In this article, the amplitude-squeezed local oscillator (LO) field at 428.8 nm is generated from a high efficiency single-pass second-harmonic generation in a crystal pumped by femtosecond (130 fs) pulses at 857.6 nm.
Abstract: We experimentally demonstrate a novel sub-shot-noise-limited heterodyne detection scheme to measure a weak optical signal field by employing amplitude-squeezed light as the local oscillator (LO) field. The amplitude-squeezed LO field at 428.8 nm is generated from a high efficiency single-pass second-harmonic generation in a ${\mathrm{KNbO}}_{3}$ crystal pumped by femtosecond (130 fs) pulses at 857.6 nm, and the signal field is combined with the generated squeezed LO field through the crystal. An enhancement of 0.7 dB (1.4 dB inferred) in signal-to-noise ratio beyond the shot-noise limit is directly observed.
TL;DR: In this paper, the authors derived the properties of a pump-resonant singly resonant optical parametric oscillator for which the pump and one of the parametrically generated waves share a common cavity.
Abstract: We derive the properties of a pump-resonant singly resonant optical parametric oscillator for which the pump and one of the parametrically generated waves share a common cavity. Wave-vector mismatch and focusing effects are taken into account. We calculate the oscillation threshold and its dependence on emission wavelengths as the result of mode shape changes. The conversion efficiencies for signal and idler waves are calculated. It is shown that one can maximize the conversion efficiencies by optimizing mirror transmissivities. The interference effects that occur in a standing-wave geometry and the mode content of the nonresonant wave are also analyzed.
TL;DR: In this paper, a framework for studying preheating and parametric resonance after inflation without resorting to any approximations, either in gravitational perturbation theory or in the classical evolution of the field(s).
Abstract: We inaugurate a framework for studying preheating and parametric resonance after inflation without resorting to any approximations, either in gravitational perturbation theory or in the classical evolution of the field(s). We do this by numerically solving the Einstein field equations in the post-inflationary universe. In this paper we show how to compare our results to those of gauge invariant perturbation theory. We then verify the analysis of Finelli and Brandenberger (hep-ph/9809490) of super-horizon modes in m{sup 2}{phi}{sup 2} inflation, showing that they are not amplified by resonant effects. Lastly, we make a preliminary survey of the nonlinear couplings between modes, which will be important in models where the primordial metric perturbations undergo parametric amplification. {copyright} {ital 1999} {ital The American Physical Society}
TL;DR: In this paper, a stabilization method for 1/3-order subharmonic resonance with an autoparametric vibration absorber was proposed, where a damped pendulum system was attached to the main system as an absorber, in order to induce 1:2 internal resonance.
Abstract: The paper proposes a stabilization method for 1/3-order subharmonic resonance with an autoparametric vibration absorber. A main system with nonlinear spring stiffness and harmonic excitation, i.e., subjected to a sinusoidally changed magnetic force, is introduced as a model which produces 1/3-order subharmonic resonance. A damped pendulum system, whose natural frequency is in the neighborhood of one-half of the main system, is attached to the main system as an absorber, in order to induce 1:2 internal resonance. The 1/3-order subharmonic resonance which occurs in the case of locked pendulum is avoided due to energy transfer between the main system and the absorber, and due to energy dissipation by the absorber. It is also theoretically shown that a stable nontrivial steady state with respect to the 1/3-order subharmonic frequency component is changed into an unstable one due to the absorber. Experimental results show the validity of the autoparametric vibration absorber for the 1/3-order subharmonic resonance.
TL;DR: Zanchin et al. as discussed by the authors showed that the generalized Floquet exponent is a non-decreasing function of the amplitude of the noise, and they provided numerical evidence for an even stronger statement, namely that in the presence of inhomogeneous noise, each mode is larger than the maximalFloquet exponent of the system in the absence of noise.
Abstract: Explosive particle production due to parametric resonance is a crucial feature of reheating in inflationary cosmology. Coherent oscillations of the inflaton field lead to a periodically varying mass in the evolution equation of matter and gravitational fluctuations and often induce a parametric resonance instability. In a previous paper [V. Zanchin {ital et al.}, Phys. Rev. D {bold 57}, 4651 (1998)] it was shown that homogeneous (i.e. space-independent) noise leads to an increase of the generalized Floquet exponent for all modes, at least if the noise is temporally uncorrelated. Here we extend the results to the physically more realistic case of spatially inhomogeneous noise. We demonstrate{emdash}modulo some mathematical fine points which are addressed in a companion paper{emdash}that the Floquet exponent is a non-decreasing function of the amplitude of the noise. We provide numerical evidence for an even stronger statement, namely that in the presence of inhomogeneous noise, the Floquet exponent of each mode is larger than the maximal Floquet exponent of the system in the absence of noise. {copyright} {ital 1999} {ital The American Physical Society}
01 Jan 1999
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