共查询到20条相似文献,搜索用时 31 毫秒
1.
ZHANGLi CAOLi WUDa-Jin 《理论物理通讯》2003,40(6):659-664
Applying the method of the unified colored noise approximation and phase lock, we study in this paper the stationary intensity distribution of the single-mode laser driven by colored pump noise with cross-correlation between the real and imaginary parts of the quantum noise. We present a thorough discussion of how the cross-correlation λq between the real and imaginary parts of the quantum noise and the self-correlation time τ of the pump noise determine the behaviors of the stationary distribution Qst(I), the mean (I), and the variance λ2(0) of the laser intensity. It is shown that cross-correlation intensity λq of the complex quantum noise can induce a first-order-like transition. When the pump noise is colored noise (τ≠0), improving the pump parameters monotonously will make the curves of Qst(I) exhibit reentrant phase transition. The fluctuations of laser intensity are strongly influenced by λq and τ when the laser is operated near or below threshold. Especially when τ≠0, the heights of the peaks of the curves of λ2(0)-α0 and α3(0)-α0, (here a0 is the net gain coefficient) go up as λq increases. However the entire curves λ2(0)-α0 and λ3(0)-α0 are abruptly suppressed when λq = 1, in similarity to phase transition of stationary intensity distribution. 相似文献
2.
CHEN Li-Mei CAO Li WU Da-Jin GE Guo-Qin 《理论物理通讯》2005,44(4):638-642
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. 相似文献
3.
Intensity Correlation Function of a Single-Mode Laser Driven
by Two Colored
Noises with Colored Cross-Correlation 总被引:1,自引:0,他引:1
HANLi-Bo CAOLi WUDa-Jin WANGJun 《理论物理通讯》2004,42(1):59-63
By using the linear approximation method, the intensity correlation function and the intensity correlation time are calculated in a gain-noise model of a single-mode laser driven by colored cross-correlated pump noise and quantum noise, each of which is colored. We detect that, when the cross-correlation between both noises is negative, the behavior of the intensity correlation function C(t) versus time t, in addition to decreasing monotonously, also exhibits several other cases, such as one maximum, one minimum, and two extrema (one maximum and one minimum), i.e., some parameters of the noises can greatly change the dependence of the intensity correlation function upon time. Moreover, we find that there is a minimum Tmin in the curve of the intensity correlation time versus the pump noise intensity, and the depth and position of Train strongly depend on the quantum noise self-correlation time T2 and cross-correlation time T3. 相似文献
4.
LI Tai-Quan DONG Ping YANG Hong-Quan HAN Li-Bo 《理论物理通讯》2005,44(2):288-292
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. 相似文献
5.
The dynamical properties of two-mode ring laser with different values of mode coupling constants are investigated by the full saturation laser theory with an injected signal. By a one-dimensional approximation, the intensity correlation time Tc and effective eigenvalue λeff11 are calculated. The effects of backscattering and injected signal are discussed. 相似文献
6.
HAN Li-Bo CAO Li WU Da-Jin WANG Jun 《理论物理通讯》2004,42(7)
By using the linear approximation method, the intensity correlation function and the intensity correlation time are calculated in a gain-noise model of a single-mode laser driven by colored cross-correlated pump noise and quantum noise, each of which is colored. We detect that, when the cross-correlation between both noises is negative, the behavior of the intensity correlation function C(t) versus time t, in addition to decreasing monotonously, also exhibits several other cases, such as one maximum, one minimum, and two extrema (one maximum and one minimum), i.e., some parameters of the noises can greatly change the dependence of the intensity correlation function upon time. T3. 相似文献
7.
8.
采用线性化近似,计算了由具有色关联的受偏置信号调制的色泵噪声和色量子噪声驱动 的单模激光增益模型的光强相对涨落,发现相对涨落随噪声强度的变化曲线中存在极小值,分析了偏置信号的强度、周期信号频率、噪声间的互关联强度和互关联时间对曲线的影响; 对单模激光增益模型在偏置信号调制和直接信号调制两种方式下的输出光强相对涨落进行了比较,发现光强涨落与偏置信号的强度密切相关.
关键词:
偏置信号调制
光强相对涨落
线性化近似 相似文献
9.
10.
Time evolution of the intensity correlation function in a single-mode laser driven by both the coloured pump noise with signal modulation and the quantum noise with cross-correlation between the real and imaginary parts
下载免费PDF全文
![点击此处可从《中国物理》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Using the linear approximation, we have studied the time evolution of intensity correlation function C(t) in a single-mode laser driven by both the colored pump noise with signal modulation and the quantum noise with cross-correlation between its real and imaginary parts. In the case of the pump noise self-correlation time, we find that the time evolution of C(t) varies with modulation signal frequency Ω, amplitude B, and net gain ɑ0. (i) As the Ω increases, the time evolution of C(t) experiences a process changing from the monotonous descension to the descension with a flat appearing initially, and finally to the a form of damping oscillation; (ii) As the B increases, it experiences from monotonous descension to the appearance of a maximum; (iii) As the net gain ɑ0 increases, it experiences a process repeatedly changing from the monotonous descension to monotonous ascension, and to the appearance of a maximum, finally to monotonous descension again. However, in the case of, the time evolution of C(t) only exhibits a form of damping oscillation . 相似文献
11.
Defining the quantity K as the signal-to-noise ratio (SNR) and the normalized intensity fluctuation C(0) 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. 相似文献
12.
Considering a single-mode laser system with cross-correlated additive colored noise and multiplicative colored noise, we study the effects of correlation among noises on the normalized intensity correlation function C(s).C(s) is derived by means of the projection operator method. 相似文献
13.
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. 相似文献
14.
By means of linear approximation method, we derive and discuss the intensity correlation function, correlation time, and power spectrum for the gain-noise model of a single-mode laser driven by multiplicative colored and additive white noises with δ-correlation form. It is found that: (1) The negative correlation between noises makes the evolution of the intensity correlation function with the time showing two forms: the monotonic attenuation and presence of the positive maximum value; while corresponding to all points on the critical line of the parameter graph for illustrating two forms, the evolution curve of the intensity correlation function with the time exhibits the initial plateau. (2) Due to the existence of the negative correlation between noises, an obvious character for the change of the intensity correlation time with the pump noise strength is that it has a crest value, and the relaxation process of the laser is slower-down than that of two independent noises. (3) The power spectrum exhibits only one peak. 相似文献
15.
X. Luo S. Zhu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,19(1):111-117
A two-dimensional decoupling theory is developed when colored noise is included in a nonlinear dynamical system. By a functional
analysis, the colored noise is transformed to an effective noise that includes the noise correlation time, the mean dynamical
variable, and the original noise strength. When the two-dimensional decoupling theory is applied to single-mode and two-mode
dye laser systems, the mean, variance, and effective eigenvalue of laser intensity are calculated. Excellent agreement between
theoretical analysis, numerical simulations, and experimental measurements are obtained. It is seen that the increase of noise
correlation time can reduce the fluctuations in the laser system. It is also shown that there is relatively large fluctuation
in the phase when the laser undergoes from thermal light to coherent light when the theory is applied to a single mode dye
laser.
Received 20 August 2001 and Received in final form 4 December 2001 相似文献
16.
采用交叉色关联的加性色噪声和乘性色噪声驱动的单模激光立方模型,通过诺维科夫理论和福克斯近似以及斯特拉托诺维奇近似,得到反映激光统计性质的强度关联函数C的表达式;研究关联时间τ、净增益系数a0和交叉关联强度λ对强度关联函数C的影响.数值模拟发现,在阈值以上(a0>0)时,关联函数C随关联时间τ的增大而增大;在阈值以下(a0<0)时,关联函数C随关联时间τ的增大而减小.无论在阈值以上还是阈值以下,关联函数C均随交叉关联强度λ的增大而减小.在C-a0曲线上存在单峰.
关键词:
单模激光
交叉关联
强度涨落
强度关联函数 相似文献
17.
We investigate the statistical properties of two single-mode dye-laser models-the colored-loss-noise model and the colored-gain-noise model. Analytic expressions of the probability,the mean and the variance of the steady-state laser intensity are obtained through the unified expansion theory [Phys. Rev. A43 (1991) 700]. By comparison we find that when the cavity decay rate for the electric field is large and the pump parameter a0 is small, the differences of the results of the two laser models are small. Otherwise, the differences are large. And the correlation time of the noise has very obvious influence on the results of the two models. 相似文献
18.
The decoupling theory is employed to analyze the multiplicative colored noise in a single mode laser system. Steady state intensity distribution function is derived when colored noise is included in the laser system. The first-order-like phase transition driven by multiplicative colored noise is investigated and compared with the case of multiplicative white noise. It is shown that the noise correlation time can affect the parameter plane of the first-order-like phase transition. The steady state intensity distributions in a laser system is changed greatly with noise correlation time τ. 相似文献
19.
HE Ying ZHU Shiqun LING Yinsheng 《Chinese Journal of Lasers》2002,11(2):99-104
The decoupling theory is employed to analyze the multiplicative colored noise in a single mode laser system. Steady state intensity distribution function is derived when colored noise is included in the laser system. The first-order-like phase transition driven by multiplicative colored noise is investigated and compared with the case of multiplicative white noise. It is shown that the noise correlation time can affect the parameter plane of the first-order-like phase transition. The steady state intensity distributions in a laser system is changed greatly with noise correlation time τ. 相似文献