A single-mode laser noise model driven by quadratic colored pump noise and biased amplitude modulationsignal is proposed.The analytic expression of signal-to-noise ratio is calculated by using a new linearized procedu...A single-mode laser noise model driven by quadratic colored pump noise and biased amplitude modulationsignal is proposed.The analytic expression of signal-to-noise ratio is calculated by using a new linearized procedure.Itis found that there are three different typies of stochastic resonance in the model:the conventional form of stochasticresonance,the stochastic resonance in the broad sense,and the bona fide SR.展开更多
In this Letter, we propose a novel constellation-shaping carrier-less amplitude and phase （CAP） modulation scheme to alleviate the systematic nonlinearity in visible light communication （VLC） systems. A simple geo...In this Letter, we propose a novel constellation-shaping carrier-less amplitude and phase （CAP） modulation scheme to alleviate the systematic nonlinearity in visible light communication （VLC） systems. A simple geo- metric transformation shaping method is employed to convert the normal square lattice constellation into multi- ple circular constellations. The feasibility and performance are investigated and experimentally demonstrated by a 1.25 Gb/s CAP-modulated VLC system. The results indicate that the circular constellation has better resis- tance to systematic nonlinearity compared with a rectangular constellation. The dynamic range of input signal peak-to-peak values promotes 20% at a low bias voltage nonlinear area and 50% at a high bias voltage nonlinear area. To the best of our knowledge, this is the first time constellation-shaping CAP has ever been reported in indoor high data rate VLC systems.展开更多
正交(IQ)调制器在传统定标方法中存在定标速度慢和数据复杂难处理的问题,在一些实际应用场合无法提供相互正交且幅值为2倍半波电压的射频信号。为了解决上述问题,提出一种基于调制相位的IQ调制器快速精确定标方法,在不加射频条件下实现...正交(IQ)调制器在传统定标方法中存在定标速度慢和数据复杂难处理的问题,在一些实际应用场合无法提供相互正交且幅值为2倍半波电压的射频信号。为了解决上述问题,提出一种基于调制相位的IQ调制器快速精确定标方法,在不加射频条件下实现对IQ调制器偏置电压的快速精确定标。测试结果表明:该方法能在45 s左右完成对IQ调制器的定标,且定标精度较高,分辨率为10 m V;能直接控制IQ调制器生成抑制载波的单边带信号。展开更多
We propose an approach to generate optical triangular-shaped pulse train with tunable repetition rate using quadrupling radio frequency(RF)modulation and optical grating dispersion-induced power fading.In this work,a ...We propose an approach to generate optical triangular-shaped pulse train with tunable repetition rate using quadrupling radio frequency(RF)modulation and optical grating dispersion-induced power fading.In this work,a piece of chirped fiber Bragg grating(FBG)is employed as the dispersive media to remove the undesired 8th harmonic in optical intensity.Thus,the generated harmonics of optical intensity can be corresponding to the first two Fourier components of typical periodic triangular pulses.This work also analyzes the impacts of the extinction ratio and the bias voltage drift on the harmonic distortion suppression ratio.After that,the value of the extinction ratio and the range of the bias voltage drift can be obtained.The advantage of this proposal is that it can generate high order frequency-multiplexed optical pulses train which can be applied in all optical signal processing and other fields.展开更多
The effect on intensity correlation time T by input signal is studied for gain-noise model of a single-mode laser driven by colored pump noise and colored quantum noise with colored cross-correlation with a bias signa...The effect on intensity correlation time T by input signal is studied for gain-noise model of a single-mode laser driven by colored pump noise and colored quantum noise with colored cross-correlation with a bias signal modulation in this paper. By using the linear approximation method, we detect that there exists maximum （i.e., resonance） in the curve of the intensity correlation time T upon bias current io when the noise correlation coefficient λ is positive; and there exists minimum （i.e., suppression） in the T-io curve when λ is negative. And whenλ is zero, T increases monotonously with increasing io. Furthermore, the curve of T upon the signal frequency Ω is also studied. Our study shows that no matter what the value of λ is, there exists minimum （i.e., suppression） in the T-Ω curve.展开更多
By using the linear approximation method, the intensity correlation function is calculated for a single-mode laser modulated by a bias signal and driven by colored pump and quantum noises with colored cross-correlatio...By using the linear approximation method, the intensity correlation function is calculated for a single-mode laser modulated by a bias signal and driven by colored pump and quantum noises with colored cross-correlation. We found that, when the correlation time between the two noises is very short, the behavior of the intensity correlation function versus the time, in addition to decreasing monotonously, also exhibits several cases, such as one maximum, one minimum, and two extrema. When the correlation time between the two noises is very long, the behavior of the intensity correlation function exhibits oscillation and the envelope is similar to the case of short cross-correlation time.展开更多
Defining the quantity K as the signal-to-noise ratio （SNR） and the normalized intensity fluctuation C（O） of a single-mode laser for bias signal modulation driven by color noises with colored correlation, the whole...Defining the quantity K as the signal-to-noise ratio （SNR） and the normalized intensity fluctuation C（O） of a single-mode laser for bias signal modulation driven by color noises with colored correlation, the whole output properties of the laser system is described by K. It is found that there is a maximum in the curves of K versus D, Q, and io. The optimization parameters are gained.展开更多
基金Supported by National Natural Science Foundation of China under Grant No.10275025
文摘A single-mode laser noise model driven by quadratic colored pump noise and biased amplitude modulationsignal is proposed.The analytic expression of signal-to-noise ratio is calculated by using a new linearized procedure.Itis found that there are three different typies of stochastic resonance in the model:the conventional form of stochasticresonance,the stochastic resonance in the broad sense,and the bona fide SR.
文摘In this Letter, we propose a novel constellation-shaping carrier-less amplitude and phase （CAP） modulation scheme to alleviate the systematic nonlinearity in visible light communication （VLC） systems. A simple geo- metric transformation shaping method is employed to convert the normal square lattice constellation into multi- ple circular constellations. The feasibility and performance are investigated and experimentally demonstrated by a 1.25 Gb/s CAP-modulated VLC system. The results indicate that the circular constellation has better resis- tance to systematic nonlinearity compared with a rectangular constellation. The dynamic range of input signal peak-to-peak values promotes 20% at a low bias voltage nonlinear area and 50% at a high bias voltage nonlinear area. To the best of our knowledge, this is the first time constellation-shaping CAP has ever been reported in indoor high data rate VLC systems.
文摘正交(IQ)调制器在传统定标方法中存在定标速度慢和数据复杂难处理的问题,在一些实际应用场合无法提供相互正交且幅值为2倍半波电压的射频信号。为了解决上述问题,提出一种基于调制相位的IQ调制器快速精确定标方法,在不加射频条件下实现对IQ调制器偏置电压的快速精确定标。测试结果表明:该方法能在45 s左右完成对IQ调制器的定标,且定标精度较高,分辨率为10 m V;能直接控制IQ调制器生成抑制载波的单边带信号。
基金supported by the Fundamental Research Funds of the Central Universities(No.2015YJS004)
文摘We propose an approach to generate optical triangular-shaped pulse train with tunable repetition rate using quadrupling radio frequency(RF)modulation and optical grating dispersion-induced power fading.In this work,a piece of chirped fiber Bragg grating(FBG)is employed as the dispersive media to remove the undesired 8th harmonic in optical intensity.Thus,the generated harmonics of optical intensity can be corresponding to the first two Fourier components of typical periodic triangular pulses.This work also analyzes the impacts of the extinction ratio and the bias voltage drift on the harmonic distortion suppression ratio.After that,the value of the extinction ratio and the range of the bias voltage drift can be obtained.The advantage of this proposal is that it can generate high order frequency-multiplexed optical pulses train which can be applied in all optical signal processing and other fields.
基金The Joint Laboratory of Quantum Optoelectronics and the Theory of Bivergentum and Beijing International Scientific and Technological Cooperation Base of Information Optoelectronics and Nanoheterogeneous Structure,the National Natural and Science Foundation of China(Nos.61574019,61674018,61674020)the Fund of the State Key Laboratory of Information Photonics and Optical Communications,the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20130005130001)
文摘The effect on intensity correlation time T by input signal is studied for gain-noise model of a single-mode laser driven by colored pump noise and colored quantum noise with colored cross-correlation with a bias signal modulation in this paper. By using the linear approximation method, we detect that there exists maximum （i.e., resonance） in the curve of the intensity correlation time T upon bias current io when the noise correlation coefficient λ is positive; and there exists minimum （i.e., suppression） in the T-io curve when λ is negative. And whenλ is zero, T increases monotonously with increasing io. Furthermore, the curve of T upon the signal frequency Ω is also studied. Our study shows that no matter what the value of λ is, there exists minimum （i.e., suppression） in the T-Ω curve.
文摘By using the linear approximation method, the intensity correlation function is calculated for a single-mode laser modulated by a bias signal and driven by colored pump and quantum noises with colored cross-correlation. We found that, when the correlation time between the two noises is very short, the behavior of the intensity correlation function versus the time, in addition to decreasing monotonously, also exhibits several cases, such as one maximum, one minimum, and two extrema. When the correlation time between the two noises is very long, the behavior of the intensity correlation function exhibits oscillation and the envelope is similar to the case of short cross-correlation time.
基金Key Project of Education Bureau of Hubei Province of China
文摘Defining the quantity K as the signal-to-noise ratio （SNR） and the normalized intensity fluctuation C（O） of a single-mode laser for bias signal modulation driven by color noises with colored correlation, the whole output properties of the laser system is described by K. It is found that there is a maximum in the curves of K versus D, Q, and io. The optimization parameters are gained.
