Showing papers on "Parametric oscillator published in 1968"
TL;DR: In this paper, a tunable, optical parametric oscillator using a continuous pump is reported, whose threshold was measured to be 45 mW of multimode power at.532 μ.
Abstract: A tunable, optical parametric oscillator using a continuous pump is reported. The threshold was measured to be 45 mW of multimode power at .532 μ. The efficiency was found to be 1% with 300 mW of pump power.
136 citations
TL;DR: In this paper, an analysis of a parametric oscillator with the nonlinear crystal internal to the laser is performed using self-consistency equations as the starting point, and the equations of motion of such an oscillator are derived.
Abstract: Since the fields inside a laser cavity are much higher than the external fields, an analysis of a parametric oscillator with the nonlinear crystal internal to the laser is performed. Using self-consistency equations as the starting point, the equations of motion of such an oscillator are derived. Depending on various cavity, pumping, and nonlinearity parameters, these lead to several types of oscillation with distinctly different operating characteristics: (1) efficient parametric oscillation similar to that of previous analyses; (2) inefficient parametric oscillation resulting from the fact that the nonlinear interaction drives the phases rather than the amplitudes of the signal, idler, and pump; and (3) a pulsing output from the oscillator with repetitive pulses of the signal and idler. A stability analysis of these various regions shows that they are mutually exclusive and can be experimentally chosen by changing the laser gain, the oscillator output coupling, or the strength of the nonlinear interaction. It is shown that the internal oscillator efficiency rapidly approaches the Manley-Rowe limit, as the available pump power becomes several times greater than that required for threshold. The efficiency of an external oscillator having a triply resonant optical cavity is found to be generally less than that of the corresponding internal oscillator.
76 citations
TL;DR: In this paper, a tunable optical parametric oscillator using a 5145-A argon laser as a pump and lithium niobate as the nonlinear material is reported.
Abstract: A tunable optical parametric oscillator using a 5145‐A argon laser as a pump and lithium niobate as the nonlinear material is reported. The oscillator is constructed in a manner such that the total multimode power of the pumping laser is useful for pumping the oscillator. Operation far from degenerate, combined with a relatively long crystal, leads to measured bandwidths of oscillation about ten times less than those previously reported.
71 citations
Patent•
04 Nov 1968
65 citations
TL;DR: In this article, an efficient room-temperature optical parametric oscillation was obtained using a single-mode, giant-pulse ruby laser to directly pump a crystal of LiNbO3 placed in an optical cavity resonant at both the signal and idler wavelengths and also in a cavity resonating at only the signal wavelength.
Abstract: Efficient room‐temperature optical parametric oscillation was obtained using a single‐mode, giant‐pulse ruby laser to directly pump a crystal of LiNbO3 placed in an optical cavity resonant at both the signal and idler wavelengths and also in a cavity resonant at only the signal wavelength. For the doubly resonant oscillator, 22% of the pump power was converted into signal power; for the singly resonant oscillator, conversion was 6%. The behavior of both oscillators was reproducible. Several features of the oscillator dynamics are discussed.
59 citations
TL;DR: In this article, a quantum mechanical theory of superconducting tunnel junctions including noise is developed and applied to the calculation of the frequency pulling, linewidth of the radiation, and voltage power spectrum in the ac Josephson effect.
Abstract: A quantum mechanical theory of superconducting tunnel junctions including noise is developed. The theory is applied to the calculation of the frequency pulling, linewidth of the radiation, and voltage power spectrum in the ac Josephson effect.
47 citations
47 citations
TL;DR: In this paper, the spectral characteristics of doubly and singly resonant-pulsed optical parametric oscillators are compared and it is demonstrated that the tuning accuracy of the singly-remaining oscillator is at least five times better than that of the doubly resonance oscillator.
Abstract: Spectral characteristics of doubly and singly resonant‐pulsed optical parametric oscillators are experimentally compared. It is demonstrated that the tuning accuracy of the singly resonant oscillator is at least five times better than that of the doubly resonant oscillator. In addition, a singly resonant oscillator having an efficiency as good as that of a doubly resonant oscillator is described.
44 citations
38 citations
19 citations
TL;DR: In this article, the van der Pol oscillator with delayed amplitude limiting was analyzed using the derivative-expansion method and explicit first-order expressions were obtained for the output in the nonresonant case.
Abstract: Forced oscillations of the van der Pol oscillator with delayed amplitude limiting are analyzed using the derivative-expansion method. The forcing function is taken to be either sinusoidal or white noise. The oscillator's output depends on whether the excitation is "hard" [i.e., excitation amplitude is O(1) ] or "soft" [i.e., excitation amplitude is O(\mu) , \mu is a small parameter], and whether the excitation is resonant (i.e., excitation frequency is near natural frequency) or not. Explicit first-order expressions are obtained for the output in the nonresonant case. If the excitation is soft, the steady-state output is a combination of terms having frequencies equal to those of the natural and excitation frequencies, with the forced response being dominated by the natural response. On the other hand, if the excitation is hard, the natural response fades away as time increases over a wide range of frequencies and excitation amplitudes. Consequently, the output is harmonic, having a frequency equal to the excitation frequency. In the resonant case, the steady-state output is synchronized at the excitation frequency, irrespective of whether the excitation is soft or hard. The frequency response equation is a family of curves that depends on the excitation amplitude and the delay time as parameters. The stability of these harmonic oscillations is determined. For the noise perturbed oscillator, the conditional probability distribution for the deviations from the stationary stable state is presented.
TL;DR: In this article, an analysis is given for a photoparametric up-converter system, which consists of a single triplate line with one coaxial output connected to a circulator.
Abstract: An analysis is given for a photoparametric up-converter system. The up-converter consists of a single triplate line with one coaxial output connected to a circulator, through which the pump is applied and the signal extracted. The other end of the line is connected to the photo diode via a small coupling capacitor. The light is modulated at frequencies from a few hertz to some upper limit determined by the bandwidth of the triplate circuit. This arrangement is shown to give excellent results and the limit performance, as determined only by the diode parameters may be attained by following the up-converter with a degenerate parametric amplifier using the same pump plus a varactor doubler.
Patent•
28 Jun 1968
TL;DR: In this article, an oscillator using a directional coupler is proposed as a solution to the design of efficient low-noise high-power high-frequency oscillators, which can be used to achieve injection phase lock.
Abstract: An oscillator using a directional coupler is proposed as a solution to the design of efficient low-noise high-power high-frequency oscillators. FM noise measurements are presented for microwave sources derived via varactor multipliers from several different transistor oscillators of this type. The design has an isolated port which can be used to achieve injection phase lock. This feature is used to point out some of the interesting FM noise properties of these oscillators, the knowledge of which is important in the design and application of solid-state microwave sources. Also, experimental results are given which show how a low-noise microwave source can be built using a low-frequency crystal oscillator followed by a high-order varactor multiplier.
Patent•
23 Dec 1968
TL;DR: In this paper, the authors proposed a method for compensating the temperature variation in the oscillation frequency of an oscillator wherein an impedance element, for example, a capacitor coupled to the oscillator is switched between two levels of its value, whereby the temperature variations are compensated for on an average.
Abstract: Method of and device for compensating the temperature variation in the oscillation frequency of an oscillator wherein an impedance element, for example, a capacitor coupled to the oscillator is switched between two levels of its value, whereby the temperature variation is compensated for on an average.
TL;DR: In this paper, the problem of a quantum harmonic oscillator with time-dependent frequency was considered for the case in which the initial state is a coherent one, and the problem was shown to be NP-hard.
TL;DR: In this article, it was proposed that the moving domain in a Gunn-effect sample can be regarded as a pumped capacitor and that this can be used to form a single d.c.-pumped parametric amplifier.
Abstract: It is proposed that the moving domain in a Gunn-effect sample can be regarded as a pumped capacitor and that this can be used to form a single d.c.-pumped parametric amplifier. The idling current can be supported in the resonance provided by the encapsulation. The figure of merit is calculated.
TL;DR: In this paper, an efficient room-temperature optical parametric oscillation was obtained using a single-mode, giant-pulse ruby laser to directly pump a crystal of LiNbO3 placed in an optical cavity resonant at both the signal and idler wavelengths and also in a cavity resonating at only the signal wavelength.
Abstract: Efficient room‐temperature optical parametric oscillation was obtained using a single‐mode, giant‐pulse ruby laser to directly pump a crystal of LiNbO3 placed in an optical cavity resonant at both the signal and idler wavelengths and also in a cavity resonant at only the signal wavelength. For the doubly resonant oscillator, 22% of the pump power was converted into signal power; for the singly resonant oscillator, conversion was 6%. The behavior of both oscillators was reproducible. Several features of the oscillator dynamics are discussed.
01 Mar 1968
TL;DR: Theorem 1.1.1 as mentioned in this paper was proved by Atkinson in the case ct = 1 (where the sum in (1.6) is empty) and
Abstract: 1. The following theorem, concerning solutions of (1.1) y" + [1 +f(x) + h(x) cos 2r,x]y = 0, was proved by Atkinson in the cases ct = 1 (where the sum in (1.6) is empty) and °°) for which there exists an integer a>0 satisfying
01 Sep 1968
TL;DR: In this article, conditions for spurious parametric oscillations to occur in a frequency doubler using a non-overdriven abrupt-junction varactor were derived, where the varactor was used to generate the spurious oscillations.
Abstract: Conditions are derived for spurious parametric oscillations to occur in a frequency doubler using a non-overdriven abrupt-junction varactor.
TL;DR: In this article, a description of a microwave oscillator of monotron type using a superconducting cavity is given, and a brief survey of theoretical properties shows that this type of oscillator can have good short-term frequency stability (10-14 for r=1 ms) and spectral purity (2?f/f=10-17).
Abstract: A description is given of a microwave oscillator of monotron type using a superconducting cavity. A brief survey of theoretical properties shows that this type of oscillator can have good short-term frequency stability (10-14 for r=1 ms) and spectral purity (2?f/f=10-17). After a brief description of the oscillator, experimental results on threshold current are given for starting oscillation and frequency stability; it is shown that it is possible to realize an S-band oscillator with a frequency stability better than 10-10 and capable of delivering continuous power of the order of 100 mW.
01 Feb 1968
TL;DR: In this article, three basic types of the so-called emitter-coupled oscillator are distinguished, and a broad tuning range despite the high power level is due to the fact that with a series connection of inductance and varactor it is not necessary to restrict the varactor bias to the reverse region.
Abstract: Three basic types of the so-called emitter-coupled oscillator may be distinguished. If the power output is taken from the emitter branch, the dependence of power on frequency is small up to frequencies of approximately f α/2 . An experimental power oscillator electronically tunable from 230 to 530 MHz delivers an average output power of 3.5 watts. The broad tuning range despite the high power level is due to the fact that with a series connection of inductance and varactor it is not necessary to restrict the varactor bias to the reverse region--the varactor may even be forward-biased up to slightly beyond the diode knee voltage.
01 Jan 1968
TL;DR: In this article, a parametric amplifier analysis, taking exact account of the frequency dependence of the parametrically induced impedance in the signal circuit, indicates that maximum gain occurs at a signal frequency slightly below that at which the signal and idler circuits are resonant.
Abstract: Parametric amplifier analysis, taking exact account of the frequency dependence of the parametrically induced impedance in the signal circuit, indicates that maximum gain occurs at a signal frequency slightly below that at which the signal and idler circuits are resonant.
Journal Article•
20 May 1968
TL;DR: In this article, the Schottky barrier varactor was used in a parametric amplifier with the pump frequency of 62 GHz and the pump power actually being dissipated in the varactor is about 40 mW.
Abstract: A parametric amplifier has been developed which has given measured noise figures of under 3.0 dB while operating with a gain of 15 dB and an instantaneous signal bandwidth of greater than 600 MHz. The center frequency of operation is 31 GHz. It is a degenerate amplifier with the pump frequency of 62 GHz. The pump power actually being dissipated in the varactor is about 40 mW. A recently developed Schottky barrier varactor is being used in this amplifier. It has the planar structure in that the junction is defined by etching the appropriate sized hole through a SiO/sub 2/ layer on GaAs and then depositing the anode material in the holes. Anode contact is made by a spring wire, the length of which is selected to obtain the proper diode resonance. The cut-off frequency at the bias point is about 600 GHz.