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Showing papers on "Injection locking published in 1999"


Journal ArticleDOI
TL;DR: In this paper, the authors proposed the optical injection phase-lock loop (OIPLL) for homodyne OIPLL systems with DFB lasers of summed linewidth 36 MHz, loop propagation delay of 15 ns and injection ratio less than -30 dB.
Abstract: The requirement for narrow linewidth lasers or short-loop propagation delay makes the realization of optical phase-lock loops using semiconductor lasers difficult. Although optical injection locking can provide low phase error variance for wide linewidth lasers, the locking range is restricted by stability considerations. Theoretical and experimental results for a system which combines both techniques so as to overcome these limitations, the optical injection phase-lock loop (OIPLL), are reported. Phase error variance values as low as 0.006 rad/sup 2/ (500 MHz bandwidth) and locking ranges exceeding 26 GHz were achieved in homodyne OIPLL systems using DFB lasers of summed linewidth 36 MHz, loop propagation delay of 15 ns and injection ratio less than -30 dB. Phase error variance values as low as 0.003 rad/sup 2/ in a bandwidth of 100 MHz, a mean time to cycle slip of 3/spl times/10/sup 10/ s and SSB noise density of -94 dBc/Hz at 10 kHz offset were obtained for the same lasers in an heterodyne OIPLL configuration with loop propagation delay of 20 ns and injection ratio of -30 dB.

208 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of injection locking on the nonlinear distortions of a DFB laser were investigated experimentally, where the second harmonic distortion and third harmonic distortion were measured as functions of modulation frequency for both the free-running and injection-locked laser.
Abstract: The effects of optical injection locking on the nonlinear distortions of directly modulated semiconductor distributed feedback (DFB) lasers are investigated experimentally. The second harmonic distortion (SHD) and third harmonic distortion (THD), as well as the third-order intermodulation distortion (IMD3), are measured as functions of modulation frequency for both the free-running and injection-locked lasers. Under strong injection locking with -8-dB injection ratio, the SHD and THD of the DFB laser have been suppressed by 15 dB from 2 to 4 GHz. Moreover, nearly 15-dB reduction in IMD3 has been observed from 1.4 to 3.0 GHz with the same injection conditions. We also found that the injection locking is not effective in reducing the low-frequency distortions.

99 citations


Journal ArticleDOI
TL;DR: In this article, a low-pass feedback loop from the oscillator output to the varactor tuning port was proposed to enhance the locking/capture range and phase-noise performance of FET-based voltage-controlled oscillators.
Abstract: A simple scheme for enhancing the locking/capture range and phase-noise performance of FET-based voltage-controlled oscillators (VCO's) is presented using a low-pass feedback loop from the oscillator output to the varactor tuning port. The nonlinearity of the FET provides for mixer or phase detector behavior (a self-oscillating mixer). The resulting feedback oscillator advantageously combines the principles of a conventional injection-locked oscillator (ILO) and phase-locked loop (PLL), which we refer to as an injection-locked phase-locked loop (ILPLL). The analysis suggests that the ILPLL can be designed for superior near-carrier phase-noise performance compared with conventional ILO or PLL circuits. A 10-GHz prototype was fabricated, which demonstrated a locking range more than double that of the isolated VCO injection-locking range over the same range of injected signal power.

77 citations


Journal ArticleDOI
TL;DR: In this article, the authors developed a continuum model for the aperture phase as a function of time, which results in a single partial differential equation for the phase asymptotics.
Abstract: Mutually injection-locked arrays of electronic oscillators provide a novel means of controlling the aperture phase of a phased-array antenna, thus achieving the advantages of spatial power combining while retaining the ability to steer the radiated beam. In a number of design concepts, one or more of the oscillators are injection locked to a signal from an external master oscillator. The behavior of such a system has been analyzed by numerical solution of a system of nonlinear differential equations which, due to its complexity, yields limited insight into the relationship between the injection signals and the aperture phase. In this paper, we develop a continuum model, which results in a single partial differential equation for the aperture phase as a function of time. Solution of the equation is effected by means of the Laplace transform and yields detailed information concerning the dynamics of the array under the influence of the external injection signals.

55 citations


Journal ArticleDOI
TL;DR: In this paper, a dual-wavelength distibuted-feedback (DPB) laser was used for frequency multiplication of a microwave signal by modulating one arm of a DFB and injection locking the other arm of the device on one of the modulation sidebands.
Abstract: Frequency multiplication of a microwave signal was achieved by modulating one arm of a dual-wavelength distibuted-feedback (DPB) laser device and injection locking the other arm of the device on one of the modulation sidebands. The dual-wavelength laser consists of two DFB lasers integrated with a Y-junction combiner on the same semiconductor substrate, thus making a compact device (L=500 /spl mu/m). The output of the combiner was allowed to beat on a high-speed photodetector. The resulting microwave signal had a narrow line shape superimposed on a Lorentzian pedestal and was at a multiple of the modulating radio frequency. Three regimes of operation of the laser device were also observed: chaotic, self-pulsating, and heterodyne.

53 citations


Journal ArticleDOI
TL;DR: In this paper, a single-mode fiber-based configuration for injection-locking experiments is presented, which allows one to precisely control the power and the polarization state of the light injected from the master laser into the slave laser cavity.
Abstract: A novel experimental setup for injection-locking experiments is presented. The single-mode-fiber-based configuration allows one to precisely control the power and the polarization state of the light injected from the master laser into the slave laser cavity. Different behaviors typical for injection locking with single-mode semiconductor lasers (e.g., stable injection locking, undamped relaxation oscillations, nearly degenerate four-wave mixing, period doubling, chaotic behavior) are experimentally observed and theoretically verified using a rate-equation-based model. Measurements and calculations are entirely linked analytically and thoroughly compared by means of the corresponding power spectra. The good quantitative agreement between measurements and model validates the model, the analytical approach, and the experimental setup.

51 citations


Journal ArticleDOI
TL;DR: In this paper, an experimental study of the injection-locking bandwidth and the relaxation oscillation frequency in a side-mode injection-locked semiconductor laser was carried out and the results were in good agreement with theoretical predictions.
Abstract: This paper is focused on an experimental study of the injection-locking bandwidth and the relaxation oscillation frequency in a side-mode injection-locked semiconductor laser. It is shown that, for such a laser, the injection-locking bandwidth and the relaxation oscillation frequency are related to the injection power and the wavelength of the target injection mode. At fixed launched injection power, the injection-locking bandwidth and relaxation oscillation frequency can be increased when the injection wavelength is detuned to the short-wavelength side of the free-running wavelength, while the relaxation oscillation frequency decreases when the injection wavelength is set to the long-wavelength side of the free-running wavelength. The results are in good agreement with theoretical predictions.

42 citations


Journal ArticleDOI
TL;DR: In this paper, the phases of the mode-locked frequency comb are shown to be coherent with that of the master CW laser, and the pulsewidth remains almost unchanged (<2 ps) for a broad range of injection power (-28 to -12 dBm).
Abstract: CW injection locking of mode-locked semiconductor lasers has been experimentally demonstrated. The phases of the mode-locked frequency comb are shown to be coherent with that of the master CW laser. The pulsewidth of the mode-locked laser remains almost unchanged (<2 ps) for a broad range of injection power (-28 to -12 dBm). Pulling of the entire mode-locked frequency comb by 400 MHz has been demonstrated. The coherent multifrequency source can be used as a local oscillator comb for coherent optical channelizers for ultrawide-band RF signals.

39 citations


Journal ArticleDOI
TL;DR: Synchronization of chaos generated in two Nd:YVO(4) microchip lasers is experimentally demonstrated with master-slave type I coupling schemes, and precise locking of the sustained relaxation-oscillation frequency is required.
Abstract: Synchronization of chaos generated in two Nd:YVO4 microchip lasers is experimentally demonstrated with master–slave coupling schemes. For synchronization of chaos, precise locking of the sustained relaxation-oscillation frequency is required, as is optical frequency locking. One needs to match both the pump-modulation parameters for chaos generation and the laser parameters of the two lasers to generate perfectly synchronized chaotic spectra in the master–slave type I coupling scheme.

38 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated injection locking characteristics of a fiber distributed feedback (DFB) laser operating in dual polarizations, and found that it could operate in a single polarization by injection locking.
Abstract: This paper investigated injection locking characteristics of a fiber distributed feedback (DFB) laser operating in dual polarizations, and found that it could operate in a single polarization by injection locking. The locking bandwidth was less than 10 MHz, much narrower than DFB laser diodes as a consequence of longer cavity length and resulting longer photon lifetime. As a more practical method to realize single-polarization operation of the fiber DFB laser, we proposed self-injection locking with a polarization-selective optical feedback composed of a mirror and a polarizer, and demonstrated a stable single-polarization operation.

37 citations


Journal ArticleDOI
TL;DR: In this paper, a non-optimized phase-locked loop with a phase variance of less than 0.005 rad 2 was used to measure the output power of a near-resonant external optical injection.

Patent
01 Apr 1999
TL;DR: In this article, two crystal oscillators are configured as a "plug-and-play" precision transmit-receive clock that requires no calibration during manufacture, and a turnstile circuit selects pulses from the second oscillator to trigger a receive clock.
Abstract: Two crystal oscillators are configured as a "plug-and-play" precision transmit-receive clock that requires no calibration during manufacture. A first crystal oscillator generates a transmit clock and a second crystal oscillator operates at a small offset from a harmonic of the first oscillator. A turnstile circuit selects pulses from the second oscillator to trigger a receive clock. Both the transmit and receive clocks operate at the same frequency. One edge of the receive clock is smoothly slipped, or swept, in phase across a limited range such as 0 to 36 degrees relative to the transmit clock with the slip rate set by the harmonic frequency offset. In one embodiment, a quadrature frequency-locked-loop is used to accurately control the slip rate while preventing false frequency locks. This timebase can be used to clock equivalent time radar, laser, and TDR ranging systems with picosecond accuracy. Applications include automotive backup and collision warning radars, precision radar rangefinders for fluid level sensing and robotics, and universal object/obstacle detection and ranging.

BookDOI
01 Jan 1999
Abstract: The first € price and the £ and $ price are net prices, subject to local VAT. Prices indicated with * include VAT for books; the €(D) includes 7% for Germany, the €(A) includes 10% for Austria. Prices indicated with ** include VAT for electronic products; 19% for Germany, 20% for Austria. All prices exclusive of carriage charges. Prices and other details are subject to change without notice. All errors and omissions excepted. J.R. Westra, C.J.M. Verhoeven, A. van Roermund Oscillators and Oscillator Systems

Patent
30 Jun 1999
TL;DR: In this article, a ring type oscillator circuit with a low-phase noise signal source is presented, where a first ring oscillator is injection-locked by a low phase noise source, one having a noise characteristic which meets the GSM radio standard of at least −132 dBc/Hz at a 3 MHz offset.
Abstract: Two or more equal amplitude periodic output signals which are mutually shifted in phase by an integer fraction of 360 degrees, such as 90°, are generated by injection locking a ring type oscillator circuit arrangement with a periodic low phase noise signal source. More particularly, a first ring oscillator is injection locked by a low phase noise signal source, one having a noise characteristic which meets the GSM radio standard of at least −132 dBc/Hz at a 3 MHz offset. An identical second ring oscillator is then driven with the output of the first ring oscillator. In one circuit configuration, an even numbered, e.g., a four stage ring oscillator is injection locked to a low-phase noise oscillator having a predetermined noise specification which is application specific and wherein a second even numbered stage, e.g., a four stage ring oscillator is coupled to the first ring oscillator. In a second circuit configuration, a first odd numbered, e.g., three stage ring oscillator, is injection locked to a low phase-noise oscillator and a second odd numbered, e.g., three stage ring oscillator, is injection locked to the first ring oscillator.

Journal ArticleDOI
TL;DR: In this article, a doubly-resonant type II phase-matched optical parametric oscillator that includes an intracavity waveplate for inducing mutual injection locking between the signal and the idler was analyzed.

Journal ArticleDOI
TL;DR: In this paper, high-speed optical modulation in a resonant tunneling relaxation oscillator consisting of a RTD integrated with a unipolar optical waveguide and incorporated in a package with a coplanar waveguide transmission line was reported.
Abstract: We report high-speed optical modulation in a resonant tunneling relaxation oscillator consisting of a resonant tunneling diode (RTD) integrated with a unipolar optical waveguide and incorporated in a package with a coplanar waveguide transmission line. When appropriately biased, the RTD can provide wide-bandwidth electrical gain. For wavelengths near the material band edge, small changes of the applied voltage give rise to large, high-speed electroabsorption modulation of the light. We have observed optical modulation at frequencies up to 14 GHz, associated with subharmonic injection locking of the RTD oscillation at the fundamental mode of the coplanar transmission line, as well as generation of 33 ps optical pulses due to relaxation oscillation.

Journal ArticleDOI
TL;DR: In this article, a four-element oscillator array using linearly polarized elements is designed to generate circular polarization, and the oscillators are coupled in a loop arrangement with unidirectional coupling.
Abstract: In this work, a four-element oscillator array using linearly polarized elements is designed to generate circular polarization. The oscillators are coupled in a loop arrangement with unidirectional coupling. The analysis of this new arrangement is developed and confirmed by circular polarization radiation pattern measurements showing a wide axial ratio beamwidth both in principal and diagonal planes.

Journal ArticleDOI
TL;DR: In this paper, the same authors examined the detuning equations for a semiconductor laser subject to injection and showed that a pulsating intensity regime may coexist with a stable steady state.

Journal ArticleDOI
TL;DR: In this paper, a method to mode lock a Fabry-Perot laser diode (F-P LD) by purely optical means is proposed, where two F-P modes are mutually injection-locked with the aid of injected cw light at the center frequency of the two modes.
Abstract: A method to mode lock a Fabry–Perot laser diode (F–P LD) by purely optical means is proposed. Two F–P modes are mutually injection locked with the aid of injected cw light at the center frequency of the two modes. The other F–P modes are cascadingly mode locked owing to the cavity-enhanced nondegenerate four-wave mixing in the F–P LD. The principle of the method was confirmed by observing the linewidth narrowing of the lasing longitudinal modes and the generated optical pulse train at the repetition frequency of one F–P mode spacing.

Patent
01 Apr 1999
TL;DR: In this article, two crystal oscillators are configured as a "plug-and-play" precision transmit-receive clock system that requires no calibration during manufacture, and a frequency locked loop regulates Δ by regulating the frequency of the detected receive pulses from a radio, radar, laser, ultrasonic, or TDR system.
Abstract: Two crystal oscillators are configured as a “plug-and-play” precision transmit-receive clock system that requires no calibration during manufacture. A first crystal oscillator generates a transmit clock and a second crystal oscillator generates a receive clock that operates at a small offset frequency Δ from the transmit clock. A frequency locked loop regulates Δ by regulating the frequency of the detected receive pulses from a radio, radar, laser, ultrasonic, or TDR system. The clock system further includes a wrong sideband reset circuit and a phase lock injection port. Applications include a timing system for automotive backup and collision warning radars, precision radar and laser rangefinders for fluid level sensing and robotics, precision radiolocation systems, and universal object/obstacle detection and ranging.

Journal ArticleDOI
TL;DR: In this article, the effects of injection locking a laser diode which is also subject to varying levels of optical feedback from an external reflector are investigated, and it is found that the locking range of a LM with optical feedback (LDWOF) is reduced relative to that of a solitary LM diode depending on both the increased photon lifetime and the amount of feedback.

Patent
Andreas Thomae1, Karsten Funk1, Johannes Artzner1, Reinhard Neul1, Georg Bischopink1, Markus Lutz1 
10 Mar 1999
TL;DR: In this article, two symmetrical frequencies and/or phase-shifted signals are produced for oscillation of a second oscillator (20) and for exciting of a first oscillator(10) with these signals.
Abstract: Two symmetrical frequencies and/or phase-shifted signals are produced for oscillation of a second oscillator (20) and for exciting of a first oscillator (10) with these signals. The response of the first oscillator (10) is determined for formation of a difference signal from the response. The frequency and/or the phase of the first oscillator (10) is then formed depending on the difference signal. Independent claims are included for: (a) a device for synchronizing a first oscillator with a second oscillator; and (b) a rotating rate sensor with a signal processing device.

Journal ArticleDOI
TL;DR: In this article, a dual-polarization emitting external-cavity diode laser (DP-ECDL) combined with the intrinsic polarization sensitivity of standard lithium-niobate Mach-Zehnder interferometer modulator offers a simple and flexible transmitter configuration.
Abstract: A novel approach to optical millimeter-wave (MM-wave) transmission based on laser heterodyning is presented. The use of a dual-polarization emitting external-cavity diode laser (DP-ECDL) combined with the intrinsic polarization sensitivity of standard lithium-niobate Mach-Zehnder interferometer modulator offers a simple and flexible transmitter configuration. The MM-wave signal generated by photomixing of the two wavelength-tunable laser modes of the DP-ECDL has been stabilized by employing a servo loop scheme and sideband injection locking. Penalty-free transmission of 200-Mb/s binary-amplitude shift keying and 50-Mb/s binary phase-shift keying over 25 km of standard single-mode fiber at MM-wave carrier frequency is demonstrated.

Patent
Jr. Normand T. Lemay1
21 Jun 1999
TL;DR: In this article, an apparatus and method for reducing frequency pulling is described, along with amplitude modulation techniques to eliminate spurious signals and injection locking of the VCO to the output transmitted carrier.
Abstract: The invention discloses an apparatus and method for reducing frequency pulling. Further, the invention provides amplitude modulation techniques to eliminate spurious signals and injection locking of the VCO to the output transmitted carrier. The architecture includes at least one synthesizer, a plurality of frequency dividers, an output VCO, a low pass filter, a mixer, a pretransmission filter and an amplifier connected in a manner to generate an output frequency which is non-harmonically related to the synthesizer VCO and to maintain the magnitude of the output frequency at, preferably, exactly 1.5 times higher than the VCO frequency.

Journal ArticleDOI
TL;DR: In this article, the locking performance of metal-semiconductor field effect transistor (MESFET) subharmonically injection-locked oscillator (SILO) is derived based on the use of a power series expression for MES-FET nonlinear elements.
Abstract: Subharmonically injection locking to an oscillator is an approach to obtain a stable source operated in microwave of millimeter-wave regions. In this paper, we present the formulation and results on the locking performance of metal-semiconductor field-effect transistor (MESFET) subharmonically injection-locked oscillator (SILO). Nonlinear-state equations of SILO are derived based on the use of a power series expression for MESFET nonlinear elements. The locking performance includes SILO output power, conversion gain, locking bandwidth, and the critical injection-locking signal level. The derived formulation is useful in the design of a MESFET SILO. Simulation results are shown to be in good agreement with those of experimental test measurement.

Journal ArticleDOI
TL;DR: In this paper, the authors present unified theoretical expressions for laser intensity noise in the presence of injection locking and feedback, and discuss optimum control strategies for different configurations and frequency regions, and illustrate the various effects with experimental results from Nd : YAG nonplanar ring oscillator lasers.
Abstract: We present unified theoretical expressions for laser intensity noise in the presence of injection locking and feedback. We discuss optimum control strategies for different configurations and frequency regions. We illustrate the various effects with experimental results from Nd : YAG non-planar ring oscillator lasers.

Journal ArticleDOI
TL;DR: In this paper, the design and performance of an injection-locked diode laser locked to a stabilized, single frequency, unmodulated diode was described, where the master oscillator is a grating-tuned, external cavity diode, which is stabilized on a Doppler free alkali metal resonance transition frequency via Zeeman locking.

Journal ArticleDOI
TL;DR: In this article, conditions for the injection locking of vertical-cavity laser arrays are considered, and the injection power required for locking to be achieved depends on various parameters such as the injected-field distribution and frequency as well as the array geometry and pumping strength.
Abstract: Conditions for the injection locking of vertical-cavity laser arrays are considered. The injection power required for locking to be achieved depends on various parameters such as the injected-field distribution and frequency as well as the array geometry and pumping strength. The circulating field distribution, driven by the injected field, is controlled mainly by the frequency detuning from the laser resonances as well as by the injected-field distribution.

Proceedings ArticleDOI
11 Jul 1999
TL;DR: In this paper, the beam direction is controlled by adjusting the phase difference between the injection signals, which can be generalized to two-dimensional arrays in which the beam control signals are applied to the oscillators on the perimeter of the array.
Abstract: Stephan (1986) proposed an approach to one dimensional (linear) phased array beam steering which requires only a single phase shifter. This involves the use of a linear array of voltage controlled electronic oscillators coupled to nearest neighbor. The oscillators are mutually injection locked by controlling their coupling and tuning appropriately. Stephan's approach consists of deriving two signals from a master oscillator, one signal phase shifted with respect to the other by means of a single phase shifter. These two signals are injected into the end oscillators of the array. The result is a linear phase progression across the oscillator array. Thus, if radiating elements are connected to each oscillator and spaced uniformly along a line, they will radiate a beam at an angle to that line determined by the phase gradient which is, in turn, determined by the phase difference between the injection signals. The beam direction is therefore controlled by adjusting this phase difference. Pogorzelski and York presented a formulation which facilitates theoretical analysis of the above beam steering technique. Using this formulation, the Stephan beam steering technique can be generalized to two-dimensional arrays in which the beam control signals are applied to the oscillators on the perimeter of the array. In this paper the continuum model for this two-dimensional case is developed and the dynamic solution for the corresponding aperture phase function is obtained The corresponding behavior of the resulting far-zone radiation pattern is displayed as well.

Journal ArticleDOI
TL;DR: A diode laser is injection locked to its own frequency-shifted emission by resonant phase modulation of the fed-back light, and the laser's emission frequency is shown to swing periodically through the locking range.
Abstract: We report a novel application of self-injection locking A diode laser is injection locked to its own frequency-shifted emission By resonant phase modulation of the fed-back light, the laser’s emission frequency is shown to swing periodically through the locking range The laser operates as a sweep generator driven by resonant self-injection locking