Injection locking

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

Analog study of bifurcation structures in a Van der Pol oscillator with a nonlinear restoring force

Abstract: The injection locking and chaotic transitions in a Van der Pol oscillator with a nonlinear-restoringforce term were investigated in this article via an electronic circuit. Free types of locking processes were differentiated from each other in light of local and global bifurcations. The influences of the nonlinear restoring force on the bifurcation structure were also discussed

High-repetition-rate mode-locked Er-doped fiber lasers by harmonic injection locking.

Abstract: We present a novel method for the generation of synchronized short pulses at high repetition rates from Er-doped silica fiber lasers. The method employs coupling of an optical pulse train to a passively mode-locked fiber laser. The injected signal repetition rate is slightly detuned from the modal spacing of the fiber laser, such that a subset of the latter modes is injection locked, yielding a high-repetition-rate pulse train. By injecting a 2-GHz train of relatively broad optical pulses at an average power of 100 μW, we achieved a train of 6-ps pulses at rates of 40 GHz from the harmonically locked fiber laser.

An Injection Frequency-Locked Loop—Autonomous Injection Frequency Tracking Loop With Phase Noise Self-Calibration for Power-Efficient mm-Wave Signal Sources

Abstract: This paper presents a fast and autonomous injection frequency tracking and locking technique. In the present injection-locking system, a quadrature injection-locked oscillator (QILO) is third harmonically locked to a quadrature voltage-controlled oscillator (QVCO). In the frequency tracking loop, the frequency difference between QVCO and QILO is extracted using the QILO’s amplitude modulated (AM) envelope waveform. The AM frequency of the envelope signal bears frequency difference between the two oscillators. The envelope signal is further converted to pulse signal which subsequently drives digital feedback control circuitry to update the QILO’s output frequency so that it can track the third harmonic of the injection QVCO. The frequency calibration process is purely autonomous, self-initiating whenever the AM modulated envelope waveform is generated. The feedback signal is primarily processed in the digital domain, resulting in a compact, fast, and power-efficient injection frequency-locked loop (IFLL). By incorporating a phase noise (PN) calibration routine after completing the frequency calibration, the presented IFLL resolves the intractable issue of PN degradation at the edge of the slave oscillator’s injection locking range. This results in a large injection frequency tracking range of 26.5–29.7 GHz which is only limited by the QILO’s LC tank tuning range. The IFLL realized in 0.13- $\mu \text{m}$ CMOS consumes 2.4 mW with a negligible area penalty. Overall chip size including QVCO, QILO, and IFLL is $1 \times 1$ mm2.

Injection Locked Wavelength De-Multiplexer for Optical Comb-Based Nyquist WDM System

Abstract: We report a standalone four-output wavelength de-multiplexer (de-mux) using optical injection locking for simultaneous comb tone separation, amplification and power equalization. Optical amplification from −30 to 5 dBm per output wavelength is achieved. We illustrate the flexibility of the de-mux by separating two input combs with tone spacing of 12.5 and 6.25 GHz into 12.5-GHz spaced outputs. The system performance of the de-mux is demonstrated in a 100-km Nyquist ultra-dense wavelength division multiplexed network where the de-multiplexed comb tones are each encoded with 12-GBd Nyquist polarization division multiplexed quadrature phase shift keying. Experimental results indicate a worst case 1.5-dB receiver sensitivity penalty at 1.5e-2 bit error ratio for the transmitted comb tone channels when compared with the 400-kHz linewidth comb source seeding laser.

Adjustable-chirp VCSEL-to-VCSEL injection locking for 10-Gb/s transmission at 1.55 μm

Abstract: 1.55-μm single-mode VCSEL frequency chirp behavior is investigated in under-threshold and above-threshold operating conditions for different VCSEL-to-VCSEL injection locking configurations with respect to free-running case. We experimentally evaluated the capability of adjusting the frequency chirp, reducing its value and inverting the sign. The control over the frequency chirp is obtained changing the wavelength detuning and power injection ratio between the VCSEL master and the VCSEL slave. Advantages of the chirp inversion are demonstrated for 10 Gb/s error-free propagation at 1.55-μm over 40-km standard single mode fiber without any dispersion compensation.