吸收介质中的费马原理和折射定律

通过定义复有效折射率,获得复光学路径长度,并利用费马原理研究了光在吸收介质界面的折射,获得光通过吸收介质界面时的折射定律。通过数值模拟计算可知：当入射角较大,且吸收介质的虚部较小时,传播的有效折射率可以用复折射率的实部代替计算;衰减的有效折射率随入射角的增大而变大,且虚部越大衰减的有效折射率也越大。     

上皮组织的深度分辨非线性光谱成像技术

基于多光子激发自体荧光和谐波信号的非线性光谱分辨成像技术，将多光子显微镜和光谱测量技术的优点集于一身，它可以同时获得组织内在成分的微结构和光谱特性．利用LSM510META激光扫描显微镜系统和深度分辨非线性光谱成像技术，对活体小鼠皮肤的微结构和光谱特性进行了研究．实验结果表明，深度非线性光谱分辨成像技术能够识别活体小鼠上皮组织的细胞层和基质层结构，能够监测上皮细胞的NADH、细胞内间质黄素蛋白、基质层的胶原蛋白、毛干中的角蛋白和黑色素等不同组织成分的发射光谱．实验观察部位的小鼠皮肤的HE染色、胶原纤维和弹力纤维特殊染色的结果也证明了利用深度分辨非线性光谱成像技术获得结果的准确性．随着微型、便捷的多光子显微镜系统的出现，深度分辨非线性光谱成像技术能够对上皮肿瘤组织的早期直接、实时、客观、无损地探测、诊断和监测提供可能，将在临床医学应用中具有重大意义和实用价值．     

Two-photon excited spectroscopies of ex vivo human skin endogenous species irradiated by femtosecond laser pulses

Two-photon excited spectroscopies from ex vivo human skin are investigated by using a femtosecond laser and a confocal microscope (Zeiss LSM 510 META). In the dermis, collagen is responsible for second harmonic generation (SHG); elastin, nicotinamide adenine dinucleotide (NADH), melanin and porphyrin are the primary endogenous sources of two-photon excited autofluorescence. In the epidermis, keratin, NADH, melanin and porphyrins contribute to autofluorescence signals. The results also show that the SHG spectra have the ability to shift with the excitation wavelength and the autofluorescence spectra display a red shift of the spectral peaks when increasing the excitation wavelength. These results may have practical implications for diagnosis of skin diseases.