Showing papers on "Parametric oscillator published in 1977"
TL;DR: In this paper, it was shown that the signal/noise ratio of a parametric amplifier and frequency converter operating under constant pumping conditions is equal to B expressed in units of hc2/λ5 = Bvac, i.e., to the number n of photons per mode in the converted radiation.
Abstract: A proposal is made to use the relationship between the spontaneous and stimulated multiphoton transitions in determination of the spectra] brightness B and the effective temperature of noncoherent light. It is shown that the signal/noise ratio M of a parametric amplifier and frequency converter operating under constant pumping conditions is equal to B expressed in units of hc2/λ5 = Bvac, i.e., to the number n of photons per mode in the converted radiation (this number is known as the degeneracy factor). The strong frequency and angular selectivity of the coherent frequency subtraction ensures a high resolution of the proposed "photon counter". Since the relationship M = n is independent of the rate of pumping, conversion efficiency, etc., such a counter may be considered as a new type of spectral brightness and radiation temperature standard. Another possible metrological application of the parametric amplifier noise arises from the simultaneity and close coupling of the directions of emission of the idler and signal photons. This feature may be used in a source emitting a known number of photons with known momenta and directions of emission; in particular, this approach should make it possible to determine the absolute quantum efficiency of a photomultiplier.
70 citations
TL;DR: In this paper, a reliable continuously tunable source of 16μm radiation with ∼ 1 2 kW peak power and repetition rates up to 20 pps is described, which consists of an Nd : YAG driven lithium niobate return pump parametric oscillator, with non-linear mixing of the signal and idler wavelengths in cadmium selenide.
26 citations
TL;DR: In this paper, the double junction SQUID is viewed as a parametric amplifier and mechanisms which place an upper limit on the pump frequency (and thus gain) are investigated; self-induced steps in the I•V characteristics as well as damping of the Josephson oscillation are two limiting mechanisms.
Abstract: The double‐junction SQUID is viewed as a parametric amplifier and mechanisms, which place an upper limit on the pump frequency (and thus gain), are investigated. Self‐induced steps in the I‐V characteristics as well as damping of the Josephson oscillation are shown to be two limiting mechanisms.
23 citations
TL;DR: In this article, the possibility of using a plasma as the nonlinear medium of a parametric amplifier was examined and it was found that if the intensity of the pump beam is 1011 W/cm2 an experimentally realizable device could be made to amplify beams in the 11-16 mu m range with efficiencies limited only by the Manley-Rowe relations.
Abstract: The possibility of using a plasma as the nonlinear medium of a parametric amplifier is examined. In the proposed scheme a 10.6 mu m CO2 laser is used to produce the pump beam. It is found that if the intensity of the pump beam is 1011 W/cm2 an experimentally realizable device could be made to amplify beams in the 11-16 mu m range with efficiencies limited only by the Manley-Rowe relations.
21 citations
Patent•
22 Aug 1977
TL;DR: In this paper, an optical parametric oscillator is disclosed in which the resonant radiation is separated from the pump and output radiation so that it can be manipulated without interfering with them.
Abstract: An optical parametric oscillator is disclosed in which the resonant radiation is separated from the pump and output radiation so that it can be manipulated without interfering with them. Thus, for example, very narrow band output may readily be achieved by passing the resonant radiation through a line narrowing device which does not in itself interfere with either the pump radiation or the output radiation.
19 citations
TL;DR: In this paper, the line width and level shift for the ν = 0 level of a harmonic oscillator predissociated by a linear potential were derived for C − and C + curve crossings.
14 citations
TL;DR: An exact equation for the evolution of density matrix in the coherent state representation for the open system of a single harmonic oscillator coupled to a reservoir of N oscillators was obtained in this article.
13 citations
TL;DR: In this article, it was shown that the pump energy can be converted efficiently into the Stokes component of the signal wave in an optical parametric oscillator with an LiIO3 nonlinear element.
Abstract: A report is given of the observation of stimulated Raman scattering inside the resonator of an optical parametric oscillator with an LiIO3 nonlinear element. It is shown that, under certain conditions, the pump energy can be converted efficiently into the Stokes component of the signal wave in the oscillator. The principal relationships governing the efficiency of this process are found in the quasistatic approximation. An analysis of a simultaneous system of approximate transient equations describing parametric oscillation and stimulated Raman scattering shows that spiky emission is possible. The investigated system is a new and promising modification of a Raman laser with a double optical resonator and a tunable excitation source.
10 citations
Patent•
30 Nov 1977TL;DR: In this paper, a parametric amplifier with a beam lead dual Schottky barrier diode fabricated on a single semiconductor chip across a waveguide cavity is presented, where two anode leads are bonded to the adjacent waveguide walls for coupling to a pump source; and a common cathode lead is bonded to a signal circuit.
Abstract: A parametric amplifier having a beam lead dual Schottky barrier diode fabricated on a single semiconductor chip across a waveguide cavity. Two anode leads are bonded to the adjacent waveguide walls for coupling to a pump source; and a common cathode lead is bonded to a signal circuit. Parasitic reactances are reduced by minimizing stray capacitance and beam lead series inductance.
9 citations
Patent•
14 Nov 1977TL;DR: A microwave oscillator including a tuning varactor and a transistor in a thin film series resonant circuit is described in this paper, where the transistor is replaced by a tuning resistor.
Abstract: A microwave oscillator including a tuning varactor and a transistor in a thin film series resonant circuit.
TL;DR: An explicit formula for general harmonic oscillator brackets is derived in this article, which is particularly useful and convenient in numerical computations, and can be used to obtain a more precise harmonic bracket.
Abstract: An explicit formula for general harmonic oscillator brackets is derived. The formula is particularly useful and convenient in numerical computations.
TL;DR: In this article, the pump intensity required to achieve operation of an optical parametric oscillator based upon a resonantly enhanced four-wave mixing process is examined and the effects of a finite phase mismatch and of absorption of the generated waves are treated.
Abstract: The pump intensity required to achieve operation of an optical parametric oscillator based upon a resonantly enhanced four-wave mixing process is examined. The effects of a finite phase mismatch and of absorption of the generated waves are treated. Numerical calculations for an atomic system (Na) and two molecular systems (HCl, CO) reveal acceptably low pump intensity requirements and suggest that such a device is potentially an efficient, scalable source of tunable coherent radiation.
TL;DR: The device reported is a CdSe OPO using no dichroic elements which produces 2-mJ pulses at 16 ..mu..m with a 0.3-cm/sup -1/ bandwidth, designed to be tunable in the 15.5 to 16.5-..mu…m range.
Abstract: The device reported is a CdSe OPO using no dichroic elements which produces 2-mJ pulses at 16 ..mu..m with a 0.3-cm/sup -1/ bandwidth. The cavity was designed to be tunable in the 15.5 to 16.5-..mu..m range. The useful life is now approximately 10/sup 4/ pulses, limited by grating damage. The pump laser is the HF oscillator--amplifier previously described. The only significant change made in the HF pump was to increase the focal lengths of the beam expander lenses by a factor of 2, allowing the use of a larger spatial filter and achievement of pump energies up to 100 mJ.
TL;DR: In this paper, a small-sized solid-sate oscillator is designed using a V02 transition metal oxide polyconductor film known as moxie, which produces an output voltage of 47.5 V with a frequency of about 23 kHz.
Abstract: A small-sized solid-sate oscillator is designed using a V02 transition metal oxide polyconductor film known as moxie. The oscillator produces an output voltage of 47.5 V with a frequency of about 23 kHz. A theoretical analysis has also been mode of the operation of such oscillators together with the development of the expressions for the output voltage, current and frequency. Calculations based on the properties or polyconductors are presented for such a system. Measurements, which confirm these calculations, are performed with several commercially available polyconductors.
TL;DR: In this paper, an anisotropic harmonic oscillator in a constant magnetic field was shown to be an exactly solvable and exceedingly simple model for closed shell paramagnetism.
Dissertation•
01 Jan 1977
TL;DR: The theory of the parametric transformer is developed in the thesis, and the unusual performance characteristics are explained, as well as possible applications in such areas as power supplies, inverters and converters.
Abstract: Although parametric devices have been known for many
years, very little attention had been paid to the possibilities
of exploiting the principles involved for low frequency power conversion purposes, until tfie recent advent
of the parametric transformer. The theory of this device
is developed in the thesis, and the unusual performance
characteristics are explained. Possible application areas
are discussed, for an assessment of the future potential of
the device as a power-control element.
The operation of the parametric transformer is considered
initially on the basis of the Mathieu-Hill equations.
The stability chart for these equations is extensively used
to permit graphical interpretation of the behaviour and characteristics. As no complete theory exists for non-linear
systems with time-varying parameters, other analytical methods
are also considered, although since all of these regard the
device as a parametric oscillator they throw little light an
the inherent transformer action.
By considering the parametric-transformer as a conventional
saturable reactor with a capacitor connected across
the load winding and the control winding driven from an
alternating source, it can be placed within the perspective
of non-linear magnetic devices already known. Many possible
magnetic constructions with parallel and/or orthogonal flux. interactions are investigated, with special attention paid
to the bridged magnetic core analogue of the two-C-core
construction. The illustration of parametric coupling as
a result of flux interaction in saturable reactor devices
leads to a derivation of the overall equations directly from
the physical system.
The functions representing the magnetic structure of
the parametric transformer are first evaluated graphically,
ard using various analytical representations of the B/H
curve their explicit expressions are then formulated for
different magnetic configurations. The introduction into
the study of the concept of a relative magnetisation curve
is invaluable in explaining the current waveforms and many
other aspects of the device.
A mathematical model is established for the parametric
transformer and the system equations are solved numerically
by a digital computer. The voltage and current waveforms and
performance characteristics are demonstrated, and the correctness
of the theory is ascertained by comparison with experimental
results.
Based on considerations of losses and efficiency, the
advantages and disadvantages of parametric transformers are
discussed. Possible applications in such areas as power
supplies, inverters and converters are viewed and examples are given.
TL;DR: In this paper, a doubly degenerate parametric amplification by a point contact Josephson junction at 36 GHz was shown to achieve a net gain of 11 dB and a noise temperature less than 50 K.
Abstract: Doubly degenerate parametric amplification by a point contact Josephson junction is observed at 36 GHz. The best amplifier showed a net gain of 11 dB and a noise temperature less than 50 K.
TL;DR: In this paper, a singly resonant optical parametric oscillator utilizing a lithium iodate crystal and operating in the infrared range was used to study the dispersion of the nonlinear third-order susceptibility of chloroform.
Abstract: A description is given of a singly resonant optical parametric oscillator utilizing a lithium iodate crystal and operating in the infrared range. The pump radiation was the second harmonic of a single-mode pulse YAG laser with a periodically operated amplifier. The use of this pumping system made it possible to tune continuously the output radiation in the 0.63?3.4 ? range and to obtain an output power of ~100 kW per pulse with a line width 2?10 cm?1. Fabry-Perot frequency selectors placed inside the resonator of the parametric oscillator made it possible to reduce the line width to <0.1 cm?1 throughout the tuning range. This parametric oscillator system was used to study the dispersion of the nonlinear third-order susceptibility of chloroform.
TL;DR: In this paper, a study was made of the possibility of frequency tuning of CdSe parametric devices in a wide range of infrared wavelengths by a uniaxial external pressure.
Abstract: A study was made of the possibility of frequency tuning of CdSe parametric devices in a wide range of infrared wavelengths by a uniaxial external pressure. The tuning curves were calculated for a CdSe parametric oscillator and a down-converter operating in the 90° phase matching at pressures up to ~2500 kg/cm2.
01 Feb 1977
TL;DR: In this article, the authors examined the likelihood of encountering parametric resonance in gun tubes and found that single-round resonance is not likely to excite single round resonance, while multiple round resonance is possible.
Abstract: : This work examines the likelihood of encountering parametric resonance in gun tubes. The resonance is induced conceptually by the periodic changes in transverse stiffness induced by (i) the axial vibrations resulting from a single application of ballistic pressure - 'single round parametric resonance'. (ii) the periodic applications of ballistic pressure such as encountered in an automatic weapon - 'multiple round parametric resonance'. Results show that ballistic cycles currently employed in the 60mm MCAAAC semi automatic cannon are not likely to excite single round resonance. Ununsually brief cycles, however, are shown to be capable of producing resonance amplifications of three orders of magnitude in less than twenty cycles of axial vibration. By proper design of the pressure cycles and/or the fundamental axial frequency of the tube, this type of resonance is rather easily avoided.
TL;DR: In this paper, the authors made an investigation of a singly resonant optical parametric oscillator pumped by monochromatic and multi-mode radiation and made an analysis of the parameters of the regions of stable stimulated emission, in which 100%-efficient conversion to parametric frequencies is possible.
Abstract: An investigation is made of a singly resonant optical parametric oscillator pumped by monochromatic and multi-mode radiation An analysis is made of the parameters of the regions of stable stimulated emission, in which 100%-efficient conversion to parametric frequencies is possible Saturation effects and the pump pulse shape are allowed for in this analysis It is shown that the threshold of a singly resonant optical parametric oscillator is independent of the mode structure of the spectrum of regular pump radiation and is governed by its average intensity
Patent•
03 Feb 1977TL;DR: In this article, an inductor (L1) is coupled in series with the quartz crystal (Q), forming a series resonant circuit with the varactor diode used for frequency pulling and with a capacitive voltage divider (C1,C2).
Abstract: The quartz Colpitts oscillator can be pulled over a width frequency range and oscillates at a higher harmonic. An inductor (L1) is coupled in series with the quartz crystal (Q). The inductor forms a series resonant circuit with the varactor diode used for frequency pulling and with a capacitive voltage divider (C1,C2). The resonant circuit is tuned to the diode average capacitance. A damping resistor is coupled in parallel with the crystal and is larger than the series resonant resistance of the crystal at the working harmonic but still low enough to prevent the crystal from being excited at its fundamental.
TL;DR: In this article, a method based on describing function concept has been used to derive the frequency change in an oscillator due to the presence of harmonics, and the experimental results agree well with the theory.
Abstract: A method baaed on the describing function concept has been Used to derive the frequency change in an oscillator due to the presence of harmonics. To check the result obtained, a simple oscillator has been med. The experimental results agree well with the theory.
TL;DR: In this article, a phase-locked RC oscillator and harmonic oscillators up to the twelfth phase were used to phase-shift the output of each oscillator in phase through 360° using an unusual resistive phase shifter.
Abstract: The instrument comprises a fundamental RC oscillator at a frequency of 256 Hz, and harmonic oscillators up to the twelfth all phase-locked to the fundamental. The output of each oscillator is variable in amplitude, and in phase through 360° using an unusual resistive phase-shifter.
TL;DR: In this article, the pseudospin-phonon formalism is used to describe the influence of lattice vibrations on the occurrence of a parametric resonance in the hydrogen-bonded ferroelectrics.
Abstract: The pseudospin–phonon formalism is used to describe the influence of lattice vibrations on the occurrence of a parametric resonance in the hydrogen-bonded ferroelectrics. The theoretical results obtained show that such a resonance is considerably stabilized by the strong coupling between protons and heavy ions.
[Russian Text Ignored].
01 Jan 1977
TL;DR: In this article, a parametric amplifier of surface acoustic waves (SAW) on monolithic MIS structure was proposed, which can be operated without the Joule heating and can be used as a tunable transducer of high-frequency SAW without the microfabrication.
Abstract: We propose a new type of parametric amplifier of surface acoustic waves (SAW) on monolithic MIS structure. medium-type parametric amplifier are as follows: (1) The device can be operated without the Joule heating. (2) The pump voltage can be reduced because of the strong capacitance nonlinearity at Si-surface in MIS structure. (3) The device characteristics can be controlled by changing the gate voltage. Moreover, the device with the spatially uniform pump can be used as a tunable transducer of high-frequency SAW without the microfabrication. We develop the theory for the parametric interaction in monolithic MIS structure with the help of the crossed field model and the method of analysis of parametric interaction in propagating microwave circuits. *When the loss is neglected, we obtain the analytical expressions for the conditions under which a very high-gain amplifi- caxion occurs and the parametric generation of SAW is expected. A preliminary experiment was carried out on the n-Si/Si02/ZnO/Al structure. frequency of SAW = 222 MHz, and the pump power = 37.2 dBm. The merits of the device compared with the travelling-wave-type amplifier and the separated-
TL;DR: In this paper, the problem of resonant interaction between a harmonic oscillator and an angular momentum oscillator was treated for the case where the a.m. is initially excited while the h.o. is in its ground state.
TL;DR: In this article, a simple GaAs impatt/varactordiode oscillator/amplifier circuit is described which can be tuned over a 10% bandwidth at mid-X-band frequencies at a power level greater than 0.5 W as an oscillator, and greater than 6 dB-gain level as a reflection amplifier.
Abstract: A simple electronically tuned c.w. GaAs impatt/varactordiode oscillator/amplifier circuit is described which can be tuned over a 10% bandwidth at mid-X-band frequencies at a power level greater than 0.5 W as an oscillator, and greater than 0.8 W at the 6 dB-gain level as a reflection amplifier. Unambiguous electronic tuning without power jumps, frequency hops or ‘out-of-band’ oscillations has been achieved by paying special attention to the circuit design.