Li Yue-Gang, Sun Shuai, Lin Hui-Zu, Liu Wei-Tao
Opt Express. 2022 Jan 17;30(2):874-886. doi: 10.1364/OE.444757.
Although the theory of scattered speckles was initially established via idealization of treating the incident light as monochromatic, phenomenon and regulations of wide-spectrum speckles are yet urgent to be studied, with immense growing applications of broadband source such as femtosecond laser, light-emitting-diode and sunlight illumination. Here we quantitatively analyze the morphology and statistics of speckles produced by a point-like source with wide-spectrum, using a phase plate model to describe the scattering layer. Due to differences in induced phase related to wavelength, wide-spectrum speckle patterns appear radial divergence in intensity distribution, as well as in visibility of both speckles and that of the second-order coherence. This is significantly different from the translation-invariance of monochromatic speckles. The spatially-varying morphology and statistics of the speckles contain spatial and spectral information of the incidence, thus can be used as an indicator to achieve optical metrology or sensing with a wide-spectrum source in the scattering environment.
尽管散射散斑理论最初是通过将入射光理想化地视为单色光而建立的，但随着飞秒激光、发光二极管和太阳光照明等宽带光源的应用不断增加，宽光谱散斑的现象和规律仍亟待研究。在此，我们使用相位板模型来描述散射层，定量分析由宽光谱点状源产生的散斑的形态和统计特性。由于与波长相关的诱导相位不同，宽光谱散斑图案在强度分布上呈现径向发散，散斑以及二阶相干性的可见度也是如此。这与单色散斑的平移不变性有显著差异。散斑的空间变化形态和统计特性包含了入射光的空间和光谱信息，因此可作为一种指标，在散射环境中利用宽光谱源实现光学计量或传感。
