Dispersion pre-compensation of 15 femtosecond optical pulses for high-numerical-aperture objectives
Dispersion pre-compensation of 15 femtosecond optical pulses for high-numerical-aperture objectives
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DOI：
10.1046/j.1365-2818.1998.00357.x
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发表时间：
1998-08-01
影响因子：
2
通讯作者：
Brakenhoff, GJ
中科院分区：
文献类型：
--
作者：
Müller, M;Squier, J;Brakenhoff, GJ
双光子吸收（TPA）显微术中的激发效率强烈地依赖于激发脉冲的时间宽度--由于TPA荧光对激发强度的平方依赖性。由于其固有的大频率带宽，超短光脉冲往往会由于传播通过显微镜中的色散元件的色散而大幅加宽。本文研究了多种显微物镜的色散特性。它示出，诱导色散可以在所有情况下的脉冲短至15 fs，由于理论建模和实验数据的结果之间的良好的协议，预测的色散控制显微镜物镜的可能性一般，以及更短的脉冲，可以推断。因为对于TPA成像，由于单光子吸收过程和散射的背景与脉冲宽度无关。适当的色散预补偿-最小化焦点处的脉冲持续时间，从而最大化激发效率-在TPA显微镜中提供最佳的图像对比度。
The excitation efficiency in two-photon absorption (TPA) microscopy depends strongly - owing to the square dependence of the TPA fluorescence on the excitation intensity - on the temporal width of the excitation pulse. Because of their inherently large frequency bandwidth, ultrashort optical pulses tend to broaden substantially because of dispersion from propagation through the dispersive elements in the microscope. In this paper, the dispersion characteristics of a wide range of microscope objectives are investigated. It is shown that the induced dispersion can be pre-compensated in all cases for pulses as short as 15 fs, Because of the excellent agreement between the results from theoretical modelling and the experimental data, predictions of the possibility of dispersion control for microscope objectives in general, as well as for even shorter pulses, can be inferred. Since for TPA imaging the background due to single photon absorption processes and scattering is independent of the pulse width. proper dispersion pre-compensation - which minimizes the pulse duration at the focal point and hence maximizes the excitation efficiency - provides optimal image contrast in TPA microscopy.