Showing papers on "Injection locking published in 1979"

A simple model for phase locking of biological oscillators

Abstract: A mathematical model is presented for phase locking of a biological oscillator to a sinusoidal stimulus. Analytical, numerical and topological considerations are used to discuss the patterns of phase locking as a function of the amplitude of the sinusoidal stimulus and the relative frequencies of the oscillator and the sinusoidal stimulus. The sorts of experimental data which are needed to make comparisons between theory and experiment are discussed.

Time compensated clock oscillator

Abstract: A time compensated clock oscillator is disclosed that has a first low power oscillator that drives an output device such as a time-of-day clock, a second more precise oscillator whose output is compared to the output of the first oscillator, and develops a correction signal that is used to periodically correct the output device.

Time-dependent harmonic oscillators

Abstract: A formalism for a time-dependent harmonic oscillator is presented. The quantum-mechanical solution is developed and the Green's function is derived. Particular examples of runaway and dissipative behavior are considered.

Transmission-Type Injection Locking of GaAs Schottky-Barrier FET Oscillators

Abstract: Transmission-type injection-locked oscillators equipped with both signal-input and power-output ports are studied. A comparison with traditional reflection-type injection-locked oscillators, in which a signal is injected into the output port of the oscillator, is presented theoretically. It is shown that the Iocking range of transmission types always differs from the reflection type by a factor of G/sub s// G/sub p/ where G/sub s/ represents the maximum stable gain of the two-port oscillator and G/sub p/ represents the square root of the output power ratio of the two ports. Experiments on common-source injection-locked oscillators using GaAs FET chips are described and show that, with transmission types, a 1.8 times wider Iocking range can be obtained than with reflection types. Furthermore, investigation of FM noise for both types of injection revealed lower off-carrier FM noise for transmission types than reflection types, even though the Iocking gain of the transmission types was kept the same as that of reflection types. Thus overall features of transmission-type injection locking were found to be advantageous for FM signal amplification even though there is a minimal power loss at the signal input port.

Spectral narrowing of a flashlamp-pumped high-energy dye laser by two-stage injection locking

Abstract: This paper proposes a new scheme of multistage injection locking controlled by a narrow-band CW dye laser to obtain spectral narrowing of a high-energy flashlamp-pumped dye laser (FLPL). The spectrum of FLPL with an output energy of 23 J was successfully narrowed to 0.7 GHz by this method. A narrow-band CW radiation was injected into the cavity of a small FLPL, then its locked output emission was injected into the cavity of the high-energy FLPL. With a CW injected power of 15 mW, about 70 percent of the output energy of the final laser was concentrated into the same spectral region as the injected CW radiation. The effective power gain obtained was as large as 4 \times 10^{8} . Using coupled rate equations based on a simplified model, the injection-locking phenomena were analyzed. This model makes it possible to derive the locking efficiency as a function of the injected power in an explicit form, and gives an insight for experiments. Some performances of injection-locked operation were studied experimentally.

Generation of high-power nanosecond pulses from a Q-switched Nd:YAG oscillator using intracavity-injecting technique.

Abstract: The application of an intracavity-injecting technique to a Q-switched Nd:YAG oscillator for efficiently generating high-power nanosecond pulses is described. Nanosecond pulses produced are synchronizable, reproducible, and remarkably stable. Applications of the technique to other types of lasers are discussed.

Injection mode locking of a TEA CO2 laser on P and R transitions in the 9- and 10-Mu m bands.

Abstract: An analysis and experimental study of an injection mode-locked TEA CO2 laser operating on various transitions in the 9- and 10-μm bands are presented. Locking on 30 transitions has been obtained with peak powers of ~1 GW in the output pulse train.

Automatic locking system for an injection locked laser

Abstract: In an injection-locked laser system, a timing system for assuring the locking of an injection-locked oscillator to the frequency of a master oscillator. The system automatically controls the firing of the injection-locked oscillator in accordance with the difference in time between the production of a master oscillator pulse and the time that a predetermined population inversion level has been reached in the injection-locked oscillator as measured by a predetermined level of fluorescence produced by the injection-locked oscillator.

A simple transition-locked and polarization-forced multi-line oscillator for high-power CO2-laser systems

Abstract: Employing injection-locking techniques an oscillator configuration was found comprising in a simple way all the features required for fusion directed high-power CO2 laser systems. The oscillator provides emission in single axial modes on rotational transitions which can be freely selected by feeding fluencies of a few mW/cm2 at the particular transition into the oscillator cavity. In the same way simultaneous emission on selectable lines can be achieved. By the same principle the oscillator can be forced to emit in any orientation of polarization. The set up is relatively simple, the alignment rather uncritical, and the operation reliable. Gaussian-shaped nanosecond pulses with low forepulse power are produced with the help of a pulse cutter and saturable multiline absorber. The set up is described and its features are demonstrated by measurements.

System for optical injection phase locking and switching of microwave oscillators

Abstract: In accordance with one embodiment of the invention, a microwave signal is used to modulate a laser diode and the resultant modulated light output energy from the laser diode is applied through an optical fiber waveguide to the active solid state component in a microwave oscillator circuit such that the output signal from the microwave oscillator is phase locked to the modulation carried by the light energy. The invention allows optical injection phase locking to be achieved not only at the fundamental frequency of the modulating signal, but also at various harmonics thereof; and "on-off" switching of the microwave oscillator can be controlled simultaneously with phase locking.

Radio frequency pulse generator

Abstract: A radio frequency pulse generator for use in a pulsed radar transmitter includes a reference oscillator of one radio frequency, a second oscillator producing a different second radio frequency which differs from a multiple M of the first frequency by a given amount and a third oscillator which is injection locked by the second oscillator to produce a subharmonic frequency of the second frequency and, when not transmitting, is injection locked by the first oscillator to thereby produce its frequency.

High Effective Subharmonic Injection Locking of a Millimeter-Wave

Abstract: Effective stabilization of an IMPATT oscillator in the millimeter-wave region carI be achieved through subharmonic injection locking to a weak parasitic oscfffatfng signaI. In subharmonic injection- Iockfng experiments more than 19 dB of locking gain at 1O-MH2 locking range was obtained at a subharmonic ratio 1:2 of the main osculating frequency. At the subfrarmonics 1:4 and 1:6, the locking gain was more than 12 and 13 dB at 10 MHs, respecti~ely. Using the parasitic oaciUating signaf, higher than 32-dB gain and Ml- MHz locking range at a subhmmordc ratio 1:2 of the parasitic oscillating frequency was oMained. This locking gain was 13 rfB higher than that for tbe mafrr oscillating signal. At the subbarnrordc ratio 1:4, the gain was more than 15 dff higher. As mraaured with the spectrum arrafyzer, the oacilIathsg sigoaf which was locked by the subharmonic injection signaf afmost coincided with the injection sigrraf. These data show that the subharmonic injection locking baa high gain as compared with that using the mairI oscillating signaf.

High Effective Subharmonic Injection Locking of a Millimeter-Wave IMPATT Oscillator

Abstract: -Effective stabilization of an IMPATT oscillator in the millimeter-wave region can be achieved through subharmonic injection locking to a weak parasitic oscillating signaI. In subharmonic injection-Iocking experiments more than 19 dB of locking gain at 10-MHz locking range was obtained at a subharmonic ratio 1:2 of the main oscillating frequency. At the subharmonics 1:4 and 1:6, the locking gain was more than 12 and 13 dB at 10 MHz, respectively. Using the parasitic oscillating signal, higher than 32-dB gain and 10-MHz locking range at a subharmonic ratio 1:2 of the parasitic oscillating frequency was obtained. This locking gain was 13 dB higher than that for the main oscillating signal. At the subharmonic ratio 1:4, the gain was more than 15 dB higher. As measured with the spectrum analyzer, the oscillating signal which was locked by the subharmonic injection signal almost coincided with the injection signal. These data show that the subharmonic injection locking has high gain as compared with that using the main oscillating signal.

Control circuit for establishing voltage-controlled or injection-locked operation of a synthesizer reference oscillator

Abstract: In a synthesizer system having a reference oscillator selectively operable in either a voltage-controlled or an injection-locked mode, a circuit for effecting the appropriate mode of operation. The circuit includes an analog gate coupled between the output of a crystal oscillator and the input of the reference oscillator. The analog gate is driven by a logic element responsive to a plurality of signals indicative of specific operating conditions. In particular, the circuit assures that the reference oscillator is coupled to the crystal oscillator, that is, the reference oscillator operates in the injection locked mode, while the synthesizer PLL achieves acquisition.

Dental handpiece and oscillating circuit for driving a transducer assembly

Abstract: A dental handpiece is disclosed with a transducer assembly for holding a work tool which is caused to vibrate at substantially a resonant frequency by a variable frequency oscillator (20). The oscillator (20) sweeps through a spectrum of frequencies under control of oscillator control means (24). A maximum in the current flow through the transducer assembly occurs at a resonant frequency and is detected by maximum detecting means (22) which then generates a latch signal to stop the oscillator at substantially that resonant frequency. Hence the oscillator is correlated to the resonant frequency of the assembly, and subsequent changes in the loading conditions on the assembly do not affect the oscillator frequency.

Optical injection locking of Si impatt oscillators

Abstract: An experimental study on optical injection locking of X‐band silicon IMPATT oscillators was carried out. The locking process was achieved by modulating a cw GaAlAs laser at subharmonics of the IMPATT oscillation frequency and optically injected into the IMPATT diode. A locking range of several megahertz can be obtained at frequency ratios ranging from 4:1 to 8:1.

Millimeter-Wave Solid State Transmitter Components

Abstract: Recent trends in millimeter-wave solid state transmitter components are reviewed. Specifically, the progress of the developments of IMPATT and Gunn Oscillators, Power Combiners, phase and injection locking techniques and upconverters are presented.

Harmonic effects in locking and initiation of TRAPATT oscillations

Abstract: Injection phase locking measurements on a pulsed S-band TRAPATT oscillator at the fundamental and third harmonic frequencies are reported. Probe measurements indicate that the start of the oscillation pulse is associated with X-band frequencies, which lie in the IMPATT range for the diode, and that jitter arises in the transition to the TRAPATT mode.

FM Noise of Transmission-Type Injection-Locked GaAsFET Oscillators and Amplifiers

Abstract: FM noise performance of transmission-type injection locking was investigated using GaAsFET oscillators. Lower off-carrier FM noise for transmission-type than for reflection-type was observed when the injection power was kept equal for both types.