Stimulated Raman scattering (SRS) microscopy has the ability of noninvasive imaging of specific chemical bonds and been increasingly used in biomedicine in recent years. Two pulsed Gaussian beams are used in traditional SRS microscopes, providing with high lateral and axial spatial resolution. Because of the tight focus of the Gaussian beam, such an SRS microscopy is difficult to be used for imaging deep targets in scattering tissues. The SRS microscopy based on Bessel beams can solve the imaging problem to a certain extent. Here, we establish a theoretical model to calculate the SRS signal excited by two Bessel beams by integrating the SRS signal generation theory with the fractal propagation method. The fractal model of refractive index turbulence is employed to generate the scattering tissues where the light transport is modeled by the beam propagation method. We model the scattering tissues containing chemicals, calculate the SRS signals stimulated by two Bessel beams, discuss the influence of the fractal model parameters on signal generation, and compare them with those generated by the Gaussian beams. The results show that, even though the modeling parameters have great influence on SRS signal generation, the Bessel beams-based SRS can generate signals in deeper scattering tissues.

中文翻译：

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贝塞尔光束激发的散射组织中受激拉曼散射信号产生的模拟

受激拉曼散射（SRS）显微镜具有对特定化学键进行无创成像的能力，近年来越来越多地应用于生物医学。传统的 SRS 显微镜使用两个脉冲高斯光束，提供高横向和轴向空间分辨率。由于高斯光束的紧密聚焦，这种 SRS 显微镜难以用于对散射组织中的深层目标进行成像。基于贝塞尔光束的SRS显微镜可以在一定程度上解决成像问题。在这里，我们通过将 SRS 信号产生理论与分形传播方法相结合，建立了一个理论模型来计算由两个贝塞尔光束激发的 SRS 信号。折射率湍流的分形模型用于生成散射组织，其中通过光束传播方法对光传输进行建模。我们对含有化学物质的散射组织进行建模，计算由两个贝塞尔光束激发的 SRS 信号，讨论分形模型参数对信号产生的影响，并将它们与高斯光束产生的信号进行比较。结果表明，尽管建模参数对SRS信号的产生影响很大，但基于贝塞尔光束的SRS可以在较深的散射组织中产生信号。并将它们与高斯光束产生的比较。结果表明，尽管建模参数对SRS信号的产生影响很大，但基于贝塞尔光束的SRS可以在较深的散射组织中产生信号。并将它们与高斯光束产生的比较。结果表明，尽管建模参数对SRS信号的产生影响很大，但基于贝塞尔光束的SRS可以在较深的散射组织中产生信号。