The optical properties of benign and malignant human brain tumors were investigated to provide a new diagnosis method. We studied various samples of adult human brain tissue (male and female) in two linear (by Optical density) and nonlinear (by Z-scan method) regimes. The obtained experimental results show that optical density for malignant is more than benign tissues and the nonlinear behavior of benign and malignant tissues are completely different because the nonlinear refractive index had a negative sign for benign tumor and a positive sign for malignant tumor. Results can be used for diagnosis between benign and malignant brain tissue.

中文翻译：

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早期诊断人类选择性良恶性脑肿瘤的简单光学方法

对良性和恶性人脑肿瘤的光学特性进行了研究，以提供一种新的诊断方法。我们在两种线性（通过光密度）和非线性（通过 Z 扫描方法）方案中研究了成人脑组织（男性和女性）的各种样本。得到的实验结果表明，恶性组织的光密度大于良性组织，良性和恶性组织的非线性行为完全不同，因为非线性折射率对良性肿瘤有负号，对恶性肿瘤有正号。结果可用于脑组织良恶性的诊断。