近红外上转换成像理论模拟研究
Theoretical Simulation Study on Near Infrared Upconversion Imaging

近红外非线性成像在医疗诊断、生物科学、环境检测和安全检查等领域中应用广泛。本文结合柯林斯近似理论，推导了基频光、信号光及和频光光强分布公式，为提高和频效率及改善光束质量提供了理论依据；其次根据推导的光强分布公式，利用Matlab软件模拟了三波光强分布图像。基于相同光路，同时利用Zemax软件模拟了三波光强分布图像，并与Matlab模拟结果进行了对比分析，结果一致。最后，在Zemax软件模拟的和频光光强分布图上，增加了高斯白噪声，并通过空域滤波对图像进一步优化，图像质量得到了明显改善。本文的研究成果为上转换成像研究提供了理论支持。
Near infrared nonlinear imaging is widely used in fields such as medical diagnosis, bioscience, environmental detection, and safety checks. This article combines Collins approximation theory to derive the intensity distribution formulas for fundamental frequency light, signal light, and sum frequency light, providing a theoretical basis for improving sum frequency efficiency and beam quality; Secondly, based on the derived formula for light intensity distribution, three wave light intensity distribution images were simulated using Matlab software. Based on the same optical path, three wave intensity distribution images were simulated using Zemax software, and compared and analyzed with Matlab simulation results, which were consistent. Finally, Gaussian white noise was added to the sum frequency light intensity distribution map simulated by Zemax software, and the image was further optimized through spatial filtering, resulting in a significant improvement in image quality. The research results of this article provide theoretical support for upconversion imaging research.