Examination of Validity of Paraxial Approximation in Second Harmonic Generation Microscopy under Low Numerical Aperture
WANG Xiang-Hui, LIN Lie, CHANG Sheng-Jiang, ZHANG Hao, HAO Shu-Juan
Institute of Modern Optics, Key Laboratory of Opto-electronic Information Science and Technology (Ministry of Education), Nankai University, Tianjin 300071
Examination of Validity of Paraxial Approximation in Second Harmonic Generation Microscopy under Low Numerical Aperture
WANG Xiang-Hui, LIN Lie, CHANG Sheng-Jiang, ZHANG Hao, HAO Shu-Juan
Institute of Modern Optics, Key Laboratory of Opto-electronic Information Science and Technology (Ministry of Education), Nankai University, Tianjin 300071
摘要By using a vectorial approach, the validity of paraxial approximation in second harmonic generation (SHG) microscopy under low numerical aperture (NA) is examined when the sample is a collagen fibril. Due to the larger value of dzzx and tensorial nature of SHG, the component Ez of the focused field may have strong effect on the radiation pattern of SHG. Numerical results indicate that when the value of NA exceeds 0.3, the effect of Ez can not be neglected, which results in the invalidation of paraxial approximation in SHG microscopy despite the fact that SHG microscopy is still under low NA focusing.
Abstract：By using a vectorial approach, the validity of paraxial approximation in second harmonic generation (SHG) microscopy under low numerical aperture (NA) is examined when the sample is a collagen fibril. Due to the larger value of dzzx and tensorial nature of SHG, the component Ez of the focused field may have strong effect on the radiation pattern of SHG. Numerical results indicate that when the value of NA exceeds 0.3, the effect of Ez can not be neglected, which results in the invalidation of paraxial approximation in SHG microscopy despite the fact that SHG microscopy is still under low NA focusing.
WANG Xiang-Hui;LIN Lie;CHANG Sheng-Jiang;ZHANG Hao;HAO Shu-Juan. Examination of Validity of Paraxial Approximation in Second Harmonic Generation Microscopy under Low Numerical Aperture[J]. 中国物理快报, 2008, 25(8): 2884-2887.
WANG Xiang-Hui, LIN Lie, CHANG Sheng-Jiang, ZHANG Hao, HAO Shu-Juan. Examination of Validity of Paraxial Approximation in Second Harmonic Generation Microscopy under Low Numerical Aperture. Chin. Phys. Lett., 2008, 25(8): 2884-2887.
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2008, Vol. 25 
