Showing papers on "Injection locking published in 1982"
NEC1
TL;DR: In this article, the injected carrier density dependent refractive index in the active region of a semiconductor laser has been analyzed, and it has been found that this dependence significantly affects the injection locking properties, giving rise to a peculiar asymmetric tuning curve and dynamic instability.
Abstract: Injection locking properties of a semiconductor laser have been analyzed, taking into account the injected carrier density dependent refractive index in the active region. It has been found that this dependence significantly affects the injection locking properties, giving rise to a peculiar asymmetric tuning curve and dynamic instability. The instability originates from the intermode interaction via the modulation in the injected carrier density caused by intensity beat. The detuning dependence of the direct modulation response characteristics inside and outside of the locking range have also been examined.
646 citations
TL;DR: In this paper, the injection locking of a laser diode to FM sidebands of a second, modulated laser has been investigated and the locking to sidebands as far as 9.5 GHz removed from the fundamental lasing frequency was observed.
Abstract: The injection locking of a laser diode to FM sidebands of a second, modulated laser has been investigated. Locking to sidebands as far as 9.5 GHz removed from the fundamental lasing frequency was observed.
76 citations
53 citations
TL;DR: In this article, the effects of refractive index dependence on the active region carrier density in semiconductor laser injection locking have been examined experimentally and strong asymmetry has been observed in the relation between locked longitudinal mode intensity and the difference between an original longitudinal mode wavelength and the injecting light wavelength.
Abstract: The effects of refractive index dependence on the active region carrier density in semiconductor laser injection locking have been examined experimentally. Strong asymmetry has been observed in the relation between locked longitudinal mode intensity and the difference between an original longitudinal mode wavelength and the injecting light wavelength.
44 citations
TL;DR: In this article, a modulated multimode buried optical guide laser with a single-mode channel substrate planar master laser was used to generate picosecond singlemode optical pulses with 1 GHz repetition rate.
Abstract: We report on the generation of picosecond single‐mode optical pulses with 1‐GHz repetition rate Single‐mode operation is obtained by injection locking a modulated multimode buried optical guide laser with a single‐mode channel substrate planar master laser The power ratio of the dominant mode to the total emitted power is improved from less than 007 without to more than 09 with injection locking Detection is performed with an autocorrelator using second‐harmonic generation in a nonlinear crystal A pulsewidth of 58 ps is obtained assuming a Gaussian pulse shape Moreover, the substructure of spikes caused by multimode operation is strongly suppressed when the laser is injection locked
39 citations
TL;DR: An analysis is presented to determine if the effects of mirror fluctuations that are due to mechanical vibrations tend to randomize the phases between lasers in the array by injection locking.
Abstract: A scheme for scaling lasers involves using a phased array of lasers. A problem encountered in this scheme is that mirror fluctuations that are due, for example, to mechanical vibrations tend to randomize the phases between lasers in the array. An analysis is presented to determine if the effects of these fluctuations can be minimized by injection locking.
31 citations
TL;DR: In this paper, a holographic grating at grazing angle of incidence was used to achieve tunable, narrow bandwidth operation of a XeCl oscillator for injection locking of a ring amplifier.
Abstract: A holographic grating at grazing angle of incidence was used to achieve tunable, narrow bandwidth (0.005 nm) operation of a XeCl oscillator for injection locking of a ring amplifier. The amplifier’s narrow bandwidth output energy was constant and equal to the untuned, broadband output (∼15 mJ) in regions where injection locking was achieved. Scanning was provided by use of a stepping motor‐driven differential micrometer on the tuning mirror. This system was used to produce a laser excitation spectrum of hydroxyl radicals (OH) in a flame.
26 citations
TL;DR: In this article, an exact derivation of the pulling figure of an oscillator is presented, taking fully into account the nonlinearity of the oscillator admittance, and the effect of oscillator non-linearity on the asymmetry of the pull range is presented.
Abstract: Only approximate relations are so far available for the pulling figure of an oscillator. An exact derivation of the pulling figure is presented here, taking fully into account the nonlinearity of the oscillator admittance. Effect of the oscillator nonlinearity on the asymmetry of the pulling range is presented.
21 citations
Patent•
20 Dec 1982
TL;DR: In this paper, a multiple tone signaling device provides a piezoelectric transducer, first, second and third oscillator circuits, a first input terminal for enabling either or both of the first and second oscillators, circuitry coupling the third oscillators to the first oscillators for disabling either the first or second ones.
Abstract: A multiple tone signaling device provides a piezoelectric transducer, first, second and third oscillator circuits, a first input terminal for enabling either or both of the first and second oscillator circuits, circuitry coupling the third oscillator circuit to the first and second oscillator circuits for disabling either the first or second oscillator circuits in response thereto, and a second input terminal coupled to the third oscillator circuit for allowing control of the output of said third oscillator circuit.
18 citations
TL;DR: In this article, the spectral and modulation properties of gain-guided and index-guided laser types differ significantly, and coherent injection locking is used to achieve single mode operation and strongly damped transient response for Gbit/s direct modulation.
Abstract: Narrow stripe geometry double-heterostructure injection lasers for optical communication applications allow direct modulation up into the Gbit/s range. Modulation behavior and influence of modulation on the laser spectrum are discussed. The spectral and modulation properties of gain-guided and index-guided laser types differ significantly. Limitations arise from intensity fluctuations due to intrinsic quantum noise, dynamic instabilities, and reflected optical power, and also, in the case of analog modulation, from harmonic distortion. By coherent injection locking, single mode operation and strongly damped transient response can be achieved. Electronic circuits for Gbit/s direct modulation are discussed.
15 citations
TL;DR: In this paper, a CO 2 TEA laser was frequency tuned by means of injection locking with a tunable waveguide laser as master oscillator, using a special injection method.
Abstract: A CO 2 TEA laser was frequency tuned by means of injection locking with a tunable waveguide laser as master oscillator, using a special injection method. Injection-locking experiments were performed at different operating conditions and varying parameters such as laser lines, master oscillator power, and frequency offset from the line center.
TL;DR: In this paper, the authors report the results of an experimental study to determine the minimum required injected power to control the output frequency of a TEA CO 2 laser, where a CW CO 2 waveguide laser was used as the injection oscillator.
Abstract: We report the results of an experimental study to determine the minimum required injected power to control the output frequency of a TEA CO 2 laser. A CW CO 2 waveguide laser was used as the injection oscillator. Both the power and the frequency of the injected radiation were varied, while the TEA reasonator cavity length was adjusted to match the frequency of the injected signal. Single-longitudinal mode (SLM) TEA laser radiation was produced for injected power levels which are several orders of magnitude below those previously reported. The ratio of SLM output power to injection power exceeded 1012at the lowest levels of injected intensity.
TL;DR: In this article, the authors achieved transform-limited bandwidth in an XeF laser by injection locking a positive-branch confocal unstable resonator with 1 W of power from an Ar-ion laser at 3511 A.
Abstract: We report attainment of transform-limited bandwidth in an XeF laser by injection locking a positive-branch confocal unstable resonator with 1 W of power from an Ar-ion laser at 3511 A. A diffraction-limited beam of >2-MW power, with a bandwidth of ~50 MHz (~1 × 10−4 A), is generated. We find that since the XeF UV emission lines start from different upper vibrational levels of the B state, ~40% of the B → X energy is not available to be channeled into the locked line.
TL;DR: In this article, the authors studied the variation in the relaxation period with the shunt inductance and resistance, the Josephson critical current, and the bias current in a resistively shunted superconducting tunnel junction.
Abstract: Relaxation oscillations at subharmonics of the Josephson frequency may occur in a resistively shunted superconducting tunnel junction, where the shunt loop has a large inductance. We have studied the variation in the relaxation period with the shunt inductance and resistance, the Josephson critical current, and the bias current. Steps in the current-voltage curve were noted at bias points where the subharmonic number changed. Radiation powers of the order of a nW were coupled out of small, single, tunnel junctions at 10 GHz. Linewidths scaled with the frequency square as compared with those of the Josephson mode oscillations. Wide signals centered around harmonics of the relaxation frequency were due to amplified noise. Injection locking to a fraction of the frequency of a relatively strong signal occurred, while weaker signals were amplified. Gains up to 15 dB were achieved within a fairly large bandwidth, but the noise temperature was high. The importance of parametrically up-converted noise from low idler frequencies is emphasized.
TL;DR: In this paper, a waveguide-cavity oscillator, applicable to power-combining circuits, has been developed using probe for coupling between active device and cavity, and the control of output power, oscillation frequency, and injection locking bandwidth are performed easily.
Abstract: A waveguide-cavity oscillator, applicable to power-combining circuits, has been developed using probe for coupling between active device and, cavity. No lossy stabilizing element is required. The control of output power, oscillation frequency, and injection locking bandwidth are performed easily. Output power of 44 mW and dc-RF conversion efficiency of 33.2 percent were obtained at 9.2GHz for a single-device low-power FET oscillator. A simple technique of cascading the pretuned oscillator modules was used to construct multiple-device oscillators incorporating up to four FET's with combining efficiency of about 100 percent.
Patent•
17 May 1982
TL;DR: In this article, a GaAs FET structure with a high electric field region, or active region, contacted by source, gate and drain electrodes is provided which can be used for high speed optical detection or for microwave oscillator optical injection locking.
Abstract: A GaAs FET structure with a high electric field region, or active region, contacted by source, gate and drain electrodes is provided which can be used for high speed optical detection or for microwave oscillator optical injection locking. The device provides for efficient coupling of optical radiation into the active region through an opening in a semi-insulating substrate used to support the device. A buffer layer between the active region and the substrate prevents leakage current to the substrate, permits a larger illumination window for improved optical coupling and provides mechanical support for the FET detector. GaAs photodetectors are also provided by eliminating the gate electrode.
TL;DR: In this paper, a conceptually radical refinement of injection-locking technique based on results arising from recent research into polarization coupling phenomena in TEA CO2 lasers is reported, which possesses certain key advantages over more commonly used techniques.
TL;DR: In this article, the first observation of an injection-locked laser oscillator whose bandwidth increases with injected intensity was reported. But this was in an HgBr oscillator, and the authors did not consider the effect of injected intensity on the frequency of the oscillator.
Abstract: We report the first observation of an injection-locked laser oscillator whose bandwidth increases with injected intensity. We have seen this effect in an HgBr oscillator. Measurements of the locked oscillator bandwidth versus injected intensity are presented.
15 Jun 1982
TL;DR: In this paper, design procedures were developed for and applied to a circularly cylindrical resonant cavity combiner (CCRCC) operating in the TM /sub 020/ mode.
Abstract: Design procedures were developed for and applied to a circularly cylindrical resonant cavity combiner (CCRCC) operating in the TM /sub 020/ mode. Thirty-two (32) GaAs double-drift IMPATT diodes were power combined in such a structure yielding 313 watts average and 1043 watts peak at X-Band.
TL;DR: The time-dependent behavior of an injection-locked single-mode passively Q-switched laser may be described by three coupled first-order rate equations relating the laser gain, the absorber loss, and the optical power density as discussed by the authors.
Abstract: The time-dependent behavior of an injection locked single-mode passively Q -switched laser may be described by three coupled first-order rate equations relating the laser gain, the absorber loss, and the optical power density. Injection locking results in a substantial increase in the mean output power and the output pulse energy and higher pulsation rate than when freely running. Stability analysis allows the determination of the maximum injected power that allows pulsations.
Patent•
27 Sep 1982TL;DR: In this article, a planar transmission line is used to power two oscillators (20) with a two-terminal negative-resistance active device power source (22) such as a negative resistance diode.
Abstract: At least two oscillators (20) are power combined using planar transmission lines, e.g., microstrip, stripline, or suspended substrate. A portion (42) of each oscillator (20) is preferably implemented in suspended substrate while an impedance matching portion (24) is preferably implemented in microstrip. Each oscillator (20) comprises a two-terminal negative-resistance active device power source (22) such as a negative resistance diode. The sources (22) are all operated in phase in the even mode. Stabilizing resistors (8) connect adjacent oscillators (20) to keep the sources (22) in phase. A diplexer (29, 33) within each oscillator (20) isolates the RF output (and RF input when injection locking is employed) from the individual DC biases used for sources (22), controls out-of-band impedances, and isolates oscillators (20) from each other. The outputs of the oscillators (20) are summed at a common junction (12) via planar transmission line spokes (10) having equal lengths. In the multi-oscillator embodiment, several oscillators (20) are radially symmetrically oriented around cylindrical junction (12 ).
TL;DR: Optical wave detection by glow discharge in a DC magnetic field (PIG-type) is described in this article, where the detection sensitivity becomes at the magnetic flux density at which the electron cyclotron frequency is almost equal to the electron-neutral molecule collision frequency.
Abstract: Optical wave detection by glow discharge in a DC magnetic field (PIG-type) is described. The detection sensitivity becomes a maximum at the magnetic flux density at which the electron cyclotron frequency is almost equal to the electron-neutral molecule collision frequency. In addition, when the microwave signal exists at the same time, the injection locking effect comes into operation, and the noise power decreases. The effect is strongest when the incident microwave power is more than –10 dBm, and its frequency is equal to the electron cyclotron frequency, the frequency of the electron circular motion, or their multiples or fractions.
TL;DR: In this paper, a precision thermometer using the NQR absorption of KC10 3 has been developed, where the super-regenerative oscillators with frequency locking has been used as the sensor oscillator in order to avoid the defects of the conventional SRSO.
15 Jun 1982
TL;DR: In this paper, a total of up to 120 Gunn diodes were combined at 23 GHz by combining three or five or seven 12- or 24-device Kurokawa oscillators through short-slot couplers in conjunction with high-level injection locking.
Abstract: Powers from a total of up to 120 Gunn diodes were combined at 23 GHz by combining three or five or seven 12- or 24-device Kurokawa oscillators through short-slot couplers in conjunction with high-level injection locking. Overall power-combining efficiencies were 76-91 percent.
TL;DR: In this paper, the authors developed a scheme for coupling into an unstable resonator which is especially simple and which provides good isolation between the injecting and injected lasers without incurring extra loss of primary laser output.
Abstract: We have developed a scheme for coupling into an unstable resonator which is especially simple and which provides good isolation between the injecting and injected lasers without incurring extra loss of primary laser output. This technique exploits the nontime-reversibility of unstable resonators to obtain a better loss/isolation trade-off. No special optical components (i.e., mirrors with holes) other than those required for the unstable resonator itself are required. Minimal losses are added to the injected laser. (AIP)
TL;DR: In this paper, the synchronization of a class-C oscillator in the subharmonic mode has been investigated and the effect of the time constant of the automatic biasing circuit on the synchronization range, frequency characteristics, stability, and locking time of the oscillator has been studied.
Abstract: This paper discusses the phenomenon of synchronization of a class-C oscillator in the subharmonic mode and reports certain new phenomena. A mathematical method has been developed to account for the phenomena. The effect of the time constant of the automatic biasing circuit on the synchronization range, frequency characteristics, stability, and locking time of the oscillator has been studied. Experimental data are also presented in support of the theory.
13 Apr 1982
TL;DR: The feasibility of coherent optical fiber systems, in which a coherent laser wave is used to carry information, has been studied in this article, where a coherent optical modulation-demodulation system using a semiconductor laser transmitter and a local oscillator has been successfully demonstrated.
Abstract: The feasibility of coherent optical fiber systems, in which a coherent laser wave is used to carry information, has been studied.1,2 A coherent optical modulation-demodulation system using a semiconductor laser transmitter and a local oscillator has been successfully demonstrated.3 Direct FM characteristics for several types of AlGaAs laser have been studied for FM transmitter applications.4
TL;DR: In this article, the existence of an anomalous polarization coupling mechanism present in the TEA CO2 laser was demonstrated and a new injection technique was formulated which permits efficient injection coupling and maximises energy extraction whilst eliminating the detrimental optical feedback effects.
Abstract: We have demonstrated the existence of an anomalous polarization coupling mechanism present in the injection locked TEA CO2 laser. As a direct consequence of this work, a new injection technique has been formulated which permits efficient injection coupling and maximises energy extraction whilst eliminating the detrimental optical feedback effects to which other injection locking systems are prone.
15 Jun 1982
TL;DR: In this article, the feasibility of direct MSK generation by using injection locking for stability improvement is investigated theoretically as well as experimentally, and the experimental work deals with the development of such a system transmitting at a rate of 4 Mbits/sec, and its performance evaluation.
Abstract: In this paper the feasibility of direct MSK generation by using injection locking for stability improvement is investigated theoretically as well as experimentally. In specific, the experimental work deals with the development of such a system transmitting at a rate of 4 Mbits/sec, and its performance evaluation.
01 Jan 1982
TL;DR: In this article, a pulsed Arion laser, operating on the 3511 Ā line of the doubly ionized species, has been used to injection lock an unstable resonator XeF laser.
Abstract: A pulsed Ar‐ion laser, operating on the 3511 Ā line of the doubly ionized species, has been used to injection lock an unstable resonator XeF laser. A single longitudinal mode of the Ar‐ion laser wea selected with a Fabry‐Perot etalon, and the resulting XeF band‐width was measured to be ∼50 MHz which is the Fourier‐transform limit corresponding to the XeF laser pulse duration of ∼20 ns. Since the XeF B→X emission originates from more than one upper vibrational level, for this pulse duration it was determined that ∼60% of the total output was available to be locked to the reference oscillator line. The 2 MW output beam was also found to be near (<1.5 x) diffraction limited.