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Showing papers on "Injection locking published in 1977"


Journal ArticleDOI
TL;DR: In this article, a low-energy etalon-tuned KrF discharge laser is used as a source to injection lock a 70mJ KrF unstable resonator oscillator in a very simple configuration.
Abstract: A low-energy etalon-tuned KrF discharge laser is used as a source to injection lock a 70-mJ KrF unstable resonator oscillator in a very simple configuration. Operating parameters and synchronization are discussed. Degradation of KrF discharge laser output with time is also studied and inferred to be partly a result of absorption at 248–249 nm by CF2 formed in the discharge.

64 citations


Journal ArticleDOI
TL;DR: In this paper, a very narrow bandwidth, flashpumped dye laser is described, achieving energies up to 50 mJ at a bandwidth of less than 30 MHz, and with a divergence of 0.4 mrad.
Abstract: A tunable, very narrow bandwidth, flashpumped dye laser is described. Publse energies up to 50 mJ at a bandwidth of less than 30 MHz, and with a divergence of 0.4 mrad, are obtained. Spectral narrowing and tuning is achieved by injection locking of the pulsed laser to the radiation, of a tunable cw dye laser. The cavity is designed for single longitudinal and transverse mode operation, with a mode diameter large enough to fill the active medium.

44 citations


Journal ArticleDOI
TL;DR: In this paper, the spectral properties of a homogeneously broadened laser with pulsed excitation were investigated and it was shown that the use of appropriately space averaged quantities allows one to take into account gain saturation effects.
Abstract: The model of a homogeneously broadened laser with pulsed excitation is considered. We compute solutions of coupled non-linear differential rate equations describing the spectral properties of the emission as a function of time. It is shown that the use of appropriately space averaged quantities allows one to take into account gain saturation effects. Injected, Fabry-Perot etalon tuned and broad-band oscillator emissions are studied. Spectro-temporal evolution of the laser emission which occurs in all cases is the main result of the computations and fully supports, as expected, the previously derived analytical equations. In addition it is shown that the basic phenomenon of spectral evolution implies the existence of an "ultimate wavelength" of the emission. How to predict the optimum and limits of injection locking is discussed in terms of a "delocking time."

44 citations


Patent
Sadao Igarashi1
29 Dec 1977
TL;DR: In this article, a phase-locked loop (PLL) circuit is proposed for TV tuners, which has a voltage-controlled type oscillator, program divider, a phase detector and a low-pass filter.
Abstract: Disclosed is a phase locked loop (PLL) circuit adapted for use, for example, in TV tuners. The PLL circuit has a voltage-controlled type oscillator, program divider, a phase detector and a low-pass filter, as is the case of conventional PLL circuits, and in addition, includes means for making the phase of the variable signal input to the phase detector lag behind the phase of the reference signal when a program switch for determining the divisor number of the program divider and a power source switch are operated, or means are provided at the output side of the low-pass filter for preventing the oscillator from oscillating at a frequency higher than one octave above a preselected frequency. These means are each effective to avoid the locking of the PLL circuit at a frequency which is a multiple of the desired frequency, thereby to ensure a safe and stable operation of the circuit in which the PLL circuit is incorporated.

21 citations


Patent
12 Jan 1977
TL;DR: In a multi-element array of laser oscillators, each having a control input for adjusting the output laser light frequency thereof, apparatus for phase and frequency locking each oscillator of the array to a reference laser oscillator are used as mentioned in this paper.
Abstract: In a multi-element array of laser oscillators, each having a control input for adjusting the output laser light frequency thereof, apparatus for phase and frequency locking each laser oscillator of the array to a reference laser oscillator. An optical phase shifter cooperates with the reference laser oscillator and with a radio frequency source to provide a local oscillator energy source. Mixing of the local oscillator energy with that of a respective one of the array oscillators by photodetector and then phase detection of the mixed or down-converted signals, relative to the radio frequency source, provides a control signal for phase and frequency control of the array oscillator.

18 citations


Journal ArticleDOI
TL;DR: A novel class of unstable resonators is described in which the mode spatial distribution is altered within the resonator by a prism or axicon.
Abstract: A novel class of unstable resonators is described in which the mode spatial distribution is altered within the resonator by a prism or axicon. In the particular configuration studied in this work, the resonator beam is separated into two halves by an intracavity reflecting prism. The conditions under which the two halves of the resonator become phase locked to form a coherent mode are studied experimentally and discussed in terms of laser injection locking.

12 citations


Patent
21 Apr 1977
TL;DR: In this article, a vibration noise filtering system for use in airborne radar master oscillator, RMO, systems is disclosed, where both master and slave crystal oscillators are used, the slave oscillator being phase locked to the master oscillators governed by a phase locked loop, PLL, having a predetermined low frequency bandwidth.
Abstract: A vibration noise filtering system for use in airborne radar master oscillator, RMO, systems is disclosed. Master and slave crystal oscillators are used, the slave oscillator being phase locked to the master oscillator governed by a phase locked loop, PLL, having a predetermined low frequency bandwidth. The master oscillator is structurally coupled directly to a source of vibration of the aircraft, while the slave oscillator is isolated and supported from the vibration source by a mechanical passive isolator having a resonant frequency well within the low frequency bandwidth of the PLL. The output of the slave oscillator which is the source of the RMO signal has a phase spectral density within the phase stability requirements of a typical RMO across the operating modulating frequency ranges of both air-to-ground and air-to-air radar modes.

10 citations


Patent
14 Nov 1977
TL;DR: In this paper, a dual loop phase-locked oscillator system with priority logic gates was proposed, where one of the oscillators is operated by the input data to lock to the data rate, while the other oscillator is controlled by the output of the first oscillator to also lock to data rate.
Abstract: A dual loop phase locked oscillator system comprises a pair of phase locked oscillators coupled with priority logic gates for selectively operating each oscillator. During a lock-to-data mode, the logic gates are operated so that one of the oscillators is operated by the input data to lock to the data rate, while the other oscillator is operated by the output of the first oscillator to also lock to the data rate. During a normal mode, or coasting mode (when no data is present), each oscillator operates off the output of the other to thereby maintain oscillation at the data rate. Thus, the oscillators are selectively operated in tandem or in parallel.

7 citations


Proceedings ArticleDOI
21 Jun 1977
TL;DR: In this paper, the FM distortion in injection-locked diode oscillators is investigated both theoretically and experimentally, and it is shown that the distortion is decreased with increasing frequency and a minimum is achieved at a frequency higher than the band center.
Abstract: FM distortion in injection locked diode oscillators is investigated both theoretically and experimentally. At the lower frequency end of the locking band, the distortion is rather high. Hence the distortion is decreased with increasing frequency and a minimum is achieved at a frequency higher than the band center.

3 citations


Proceedings ArticleDOI
21 Jun 1977
TL;DR: In this article, a new injection locking process is proposed and demonstrated experimentally, where a low-frequency injection signal can be used to lock an ultra-high frequency solid-state oscillator.
Abstract: A new injection locking process is proposed and demonstrated experimentally, where a low-frequency injection signal can be used to lock an ultra-high frequency solid-state oscillator. This process has much wider locking bandwidth than the conventional subharmonic injection locking.

3 citations



Patent
20 Apr 1977
TL;DR: An injection-locked ultra-high frequency solid-state oscillator employs an injection locking method in which an ultra high frequency output power from a solid state oscillator is stabilized by injecting an output signal from another stable oscillator as discussed by the authors.
Abstract: An injection-locked ultra-high frequency solid-state oscillator employs an injection locking method in which an ultra-high frequency output power from a solid-state oscillator is stabilized by injecting an output signal from another stable oscillator. The signal injected into the solid-state oscillator has an optional frequency low enough as compared to that of the output power from the solid-state oscillator and is supplied through a bias supplying circuit or the like. Injection of such low-frequency signal produces sideband waves around the oscillation-wave from the solid-state oscillator while one of such sideband waves is trapped by a high-Q cavity resonator provided in the vicinity of a solid-state oscillating element of the solid state oscillator. The oscillation wave from the solid-state oscillator becomes low noise with the sideband wave trapped, and the frequency of the oscillation wave from the solid-state oscillator is made variable in obedience to the variation of the injection signal frequency.


Journal ArticleDOI
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.

Journal ArticleDOI
TL;DR: In this paper, the 2nd-harmonic frequency locking range of an l.s.a.mode oscillator has been studied by computer simulation, and the results show that under certain circuit conditions the second-harmony frequency locking ranges may exceed that of the fundamemtal.
Abstract: Harmonic injection locking of an l.s.a.-mode oscillator has been studied by computer simulation. The results show that under certain circuit conditions the 2nd-harmonic frequency locking range may exceed that of the fundamemtal.

ReportDOI
01 Nov 1977
TL;DR: In this article, a comb spectrum generator using SAW technology has been developed for operation at 333 MHz and higher frquencies, where the stabilization signal is provided by means of a Phase Locked Loop oscillator that is assembled from commercially available IC components.
Abstract: : Stabilized comb spectra generators using SAW Technology have been developed for operation at 333 MHz and higher frquencies. These signal sources and an additional CW source at 1984 MHz are being developed to provide precision signals for a rapid frequency hopping frequency synthesizer. The comb spectrum generator is based upon the Mode Locked SAW Oscillator (MLSO), a regenerative rf pulse oscillator. Stabilization, i.e., synchronization to a 1 MHz reference signal, is accomplished through injection locking of the MLSO at the fundamental rf frequency. The stabilization signal is provided by means of a Phase Locked Loop oscillator that is assembled from commercially available IC components. The first complete prototype consists of two four inch square circuit boards and consumes about five watts of power. This first prototype operating at 333 MHz generates the desired spectral lines (9 lines spaced 3 MHz apart) and the signal characteristics closely satisfies the goals of the program both for low FM noise and spurious signals. The judicious use of SAW filters was important for meeting the program goals. These SAW filters together with the IC components made possible a small compact package that can be even further reduced in size with further development. Preliminary results with the 828 MHz MLSO and the 1984 MHz CW source are also promising. (Author)

Journal ArticleDOI
TL;DR: In this article, an ideal Josephson element shunted by a resistance and an external linear circuit in series with a rf voltage source is analyzed from the circuit point of view.
Abstract: The system consisting of a Josephson element inside a resonant cavity biased by a current source has been analyzed from the circuit point of view. The dynamical equations for an ideal Josephson element shunted by a resistance and an external linear circuit in series with a rf voltage source are solved by a systematic perturbation theory. When the rf voltage is zero, these solutions describe the cavity induced step and for a non zero rf voltage, these solutions indicate the phenomenon of phase locking. The lock range is obtained as a function of the cavity Q, the coupling of the element to the cavity, the critical junction current and the incident power. The results are compared with the Longacre and Shapiro theory of the magnitude of the cavity induced step, the general phase locking theory of Adler and the experimental results of Stancampiano and Shapiro.

Journal ArticleDOI
TL;DR: In this article, it was shown that the second grounding pulse led to a buildup of space charge during the switching event which invariably resulted in an undesirable conductive transient lasting on the order of microseconds.
Abstract: grounding the conduction path. We found that this second grounding pulse led to a buildup of space charge during the switching event which invariably resulted in an undesirable conductive transient lasting on the order of microseconds. This transient requires a second backup gate if high isolation is required and thus diminishes the usefulness of the original switch design.' New design configurations that allow turn-on and off with two pulses at the same wavelength reduce but do not eliminate this problem to the desired degree. Such configurations were tested and the time r sponse measured. For . these configurations, the power handling capabilities can be significantly increased by using semiconducting films deposited on insulator substrates. Subsequent studies of ultrafast switching in GaAs using a single pulse were successful in eliminating these undesirable transients. Single optical pulse switching can be accomplished by using a semiconducting substrate in which the photoconductivity is rapidly quenched by the presence of a high concentration of deep traps. This approach was tested by fabricating microstrip switches on chromium doped GaAs ubstrates. The duration of the switching event can be measured by an optoelectronic sampling technique employing a silicon microstrip switch.* The results of this measurement indicate a switching time of 70 picoseconds. Lower mobilities in chromium doped GaAs require higher densities of photoinjected charge. The rapid radiationless recombination of this high density electron-hole plasma imparts a significant amount of thermal energy to the semiconducting substrate and is thought to account for the observable tendency for laser induced surface damage in this class of switch. It is therefore concluded that fast (-50 ps duration) switching will have to be performed at moderate repetition rates (<1 MHz) in order to avoid surface damage. Optoelectronic microstrip switches for slower switching do not suffer from the above mentioned problems. Microstrip switches deposited on composite CdSe-A1203 substrates have proven to be effective switches.' They may be driven directly by injection lasers and offer terminal to terminal isolation per stage of 20 dB or greater. The suitability of microstrip optoelectronic devices for microwave phase shifting applications will also be discussed.

Journal ArticleDOI
TL;DR: In this article, the frequency compliance co-efficient of a wave guide cavity X-band Gunn Oscillator has been experimentally determined by using a perturbation method and the correlation between the values obtained by these two methods has been discussed.
Abstract: Frequency compliance co-efficient of a wave guide cavity X-band Gunn Oscillator has been experimentally determined by using a perturbation method. This along with other experimentally determined oscillator parameters has been used to estimate the injection locking figure-of-merit of the oscillator. The injection locking figure-of-merit has also been measured by using conventional injection locking experiments. The correlation between the values obtained by these two methods has been discussed.

Proceedings ArticleDOI
01 Oct 1977
TL;DR: In this paper, a prototype oscillator circuit is described which uses evanescent mode resonators as housing for active devices, applied to voltage controlled oscillators, injection locked oscillators as FM-amplifiers and frequency dividers, and cavity stabilized oscillators.
Abstract: A prototype oscillator circuit is described which uses evanescent mode resonators as housing for active devices. The circuit is applied to voltage controlled oscillators, injection locked oscillators as FM-amplifiers and frequency dividers, and cavity stabilized oscillators. Design hints and electrical performance of these components are given.