Injection locking

About: Injection locking is a research topic. Over the lifetime, 4567 publications have been published within this topic receiving 60942 citations.

Millimeter-resolution long-range OFDR using ultra-linearly 100 GHz-swept optical source realized by injection-locking technique and cascaded FWM process

Abstract: In this paper, we propose and demonstrate a millimeter-resolution long-range optical frequency domain reflectometry (OFDR) using an ultra-linearly 100-GHz swept optical source realized by injection-locking technique and cascaded four-wave-mixing (FWM) process. The ultra-linear sweep is realized using an external modulation method with a linearly swept radio frequency (RF) signal. The RF signal sweeps from 16 GHz to 19.3 GHz, and the slave laser is injection-locked to the 8th-order sideband of the master laser, achieving a frequency sweeping span of ~25 GHz. By using the injection-locked frequency-swept laser as the optical source of OFDR, we obtain a spatial resolution of 4.2 mm over 10-km measurement range. A polarization beat length of 10.5 cm is measured benefiting from the high spatial resolution. To improve the spatial resolution further, FWM process is used to broaden the frequency sweeping span. Frequency sweeping span of ~100 GHz is achieved with cascaded FWM. We demonstrate a 1.1-mm spatial resolution over 2-km measurement range with the proposed ultra-linearly swept optical source.

Mode stability of radiation-coupled interinjection-locked oscillators for integrated phased arrays

Abstract: An analysis is presented of a two-element, 10-GHz array consisting of two oscillators coupled solely by means of the free-space interaction between their respective antenna elements. The oscillators are modeled as energy-storing L-C tank circuits in parallel with voltage-dependent negative conductances. A simplified far-field slot antenna model is used to derive the mutual admittance of the two antennas. Even-odd mode analysis yields the normal modes of the system, and a theorem from averaged potential theory is used to determine which mode is stable. Two microstrip Gunn diode oscillators were built to verify the essential features of the model. Oscillator frequencies, relative phases, and radiation patterns were measured as functions of the interantenna distance, and the periodic alternation of modes with distance predicted by theory was confirmed quite well. >

Injection locking of the gyrotropic vortex motion in a nanopillar

Abstract: Spin-torque oscillators (STOs) are a promising application for the spin-transfer torque effect. The major challenge lies in pushing the STO’s microwave output power to useful levels, e.g., by operating an array of STOs in a synchronized, phase-locked mode. Our experiment on metallic, giant magnetoresistance-type nanopillars focuses on the influence of external high-frequency signals on the current-driven vortex dynamics and demonstrates the injection locking of the gyrotropic mode. We find a gap of about three orders of magnitude between the high-frequency power emitted by one oscillator and the power needed for phase-locking.

Optical neuron by use of a laser diode with injection seeding and external optical feedback

Abstract: We present an all-optical neuron by use of a multimode laser diode that is subjected to external optical feedback and light injection. The shape of the threshold function, that is needed for neural operation, is controlled by adjusting the external feedback level for two longitudinal cavity modes of the laser diode individually. One of the two modes corresponds to the output of the neuron, light injection at the wavelength of this mode provides excitatory input. Light injection in the other mode provides inhibitory input. When light corresponding to two input signals is injected in the same mode, summation of input signals can be achieved. A rate-equation model is used to explain the operating principle theoretically. The proposed injection seeding neuron is built using free-space optics to demonstrate the concept experimentally. The results are in good agreement with the predictions from the rate-equation model. Some experimental results show threshold functions that are preferable from a neural-network point of view. These results agree well with injection locking theory and experiments reported in literature.

8.7 A 4-to-10.5Gb/s 2.2mW/Gb/s continuous-rate digital CDR with automatic frequency acquisition in 65nm CMOS

Abstract: Continuous-rate clock-and-data recovery (CDR) circuits with automatic frequency acquisition offer flexibility in both optical and electrical communication networks, and minimize cost with a single-chip multi-standard solution. The two major challenges in the design of such a CDR are: (a) extracting the bit-rate from the incoming random data stream, and (b) designing a wide-tuning-range low-noise oscillator. Among all available frequency detectors (FDs), the stochastic divider-based approach has the widest frequency acquisition range and is well suited for sub-rate CDRs [1]. However, its accuracy strongly depends on input transition density (0 ≤ ρ ≤ 1), with any deviation of ρ from 0.5 (50% transition density) causing 2×(ρ-0.5)×106 ppm of frequency error. In this paper, we present an automatic frequency-acquisition scheme that has unlimited range and is immune to variations in transition density. Implemented using a conventional bang-bang phase detector (BBPD), it requires minimum additional hardware and is applicable to sub-rate CDRs as well. Instead of using multiple LC oscillators that are carefully designed to cover a wide frequency range [2,3], a ring-oscillator-based fractional-N PLL is used as a digitally controlled oscillator (DCO) to achieve both wide range and low noise, and to decouple the tradeoff between jitter transfer (JTRAN) bandwidth and ring-oscillator-noise suppression.