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基于散斑强度相关函数的表面粗糙度测量方法 被引量:12
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作者 周莉莉 赵学增 郑俊丽 《光电工程》 CAS CSCD 北大核心 2004年第7期50-53,共4页
激光经过被测表面反射和散射后,通过自由空间传播至观察面上形成散斑图像,其统计分布依赖于被测表面的微观形貌。分析此散斑图像的二阶统计特性,导出了强度变化的相关函数和表面粗糙度参数之间的关系。以表面粗糙平均值Ra分别为0.1靘, ... 激光经过被测表面反射和散射后,通过自由空间传播至观察面上形成散斑图像,其统计分布依赖于被测表面的微观形貌。分析此散斑图像的二阶统计特性,导出了强度变化的相关函数和表面粗糙度参数之间的关系。以表面粗糙平均值Ra分别为0.1靘, 0.2靘, 0.4靘和0.8靘的平磨标准金属样块形成的散斑图像为例,根据强度变化相关函数的离散化定义,计算得到该相关函数值。结果表明,表面越粗糙,散斑越分散,强度变化的相关函数波动越大。因此,该参数可以反映不同的粗糙面,用其作为表征表面粗糙度的特征参数,扩大了测量范围。该方法实验系统简单,对于实际测量环境要求不高,对震动不是非常敏感,适于在线测量。 展开更多
关键词 表面粗糙度测量 散斑图像 强度相关函数
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Intensity Correlation Function of a Single-Mode Laser Driven by Two Colored Noises with Colored Cross-Correlation
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作者 HANLi-Bo CAOLi +1 位作者 WUDa-Jin WANGJun 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第1X期59-63,共5页
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... 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. 展开更多
关键词 强度相关函数 强度相关时间 线性近似理论 双色噪声 单模激光器 激光物理
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Intensity Correlation Function of a Single-Mode Laser Driven by Colored Cross-Correlation Noises in Modulation of a Bias Signal
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作者 HANLi-Bo CAOLi +1 位作者 YANGHong-Quan WUDa-Jin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第4期666-670,共5页
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
关键词 linear approximation method intensity correlation function bias signal modulation oscillation
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基于扩散相关光谱的血流检测方法研究 被引量:4
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作者 梁佳明 王晶 +1 位作者 梅建生 张镇西 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2012年第10期2749-2752,共4页
组织血流信息在临床诊断和治疗中具有重要的作用,无创血流检测是医患双方的期望。研究采用了近红外扩散相关光谱方法对生物组织血流进行无创检测,理论分析了散射光斑强度的变化和被测组织中血细胞运动状态的函数关系,建立了检测组织血... 组织血流信息在临床诊断和治疗中具有重要的作用,无创血流检测是医患双方的期望。研究采用了近红外扩散相关光谱方法对生物组织血流进行无创检测,理论分析了散射光斑强度的变化和被测组织中血细胞运动状态的函数关系,建立了检测组织血流的理论模型及检测系统。该系统通过求解组织表面散射光斑电场强度的时间自相关函数来推断组织中血细胞的运动状态,进行组织血流的定量分析。采用健康人体前臂袖带加压实验模型对该系统进行了验证,实验结果验证了该系统进行组织无创血流检测的可行性,同时也表明该系统可以提供从浅层到深层的组织血流变化信息。 展开更多
关键词 无创血流检测 扩散相关光谱 电场强度时间自相关函数
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