双光子显微成像系统群延迟色散的测量和补偿

Measurement and Compensation of Group Delay Dispersion for Two-Photon Microscopy Imaging Systems

为了对双光子显微成像系统的群延迟色散进行校正,提高双光子激发效率的目的,采用自相关仪测量的方法在自行搭建的双光子系统光路的四个位置测量飞秒激光的脉冲展宽情况,测量样品位置5个波长下最优的群延迟色散补偿值,由此拟合得到自搭建双光子系统的全波段群延迟色散补偿曲线。实验结果表明在应用此群延迟色散补偿曲线后样品位置的脉冲宽度平均减小95 fs,在两个典型激发波长(750 nm和900 nm)生物样品的荧光强度分别提高了42.7%和76.8%。结论为双光子激发效率与飞秒激光的脉冲宽度成线性反比关系。

For the purpose of correcting the group delay dispersion( GDD),improving the two-photon excitation efficiency of two-photon microscopy imaging system( TPMIS),in method of the autocorrelator mesurement,the pulse width of femtosecond laser is measured from four positions of optical path of the self-built TPMIS and also optimal GDD compensation value of five wavelengths is measured from the sample'position,thus fitted to obtain the full-band GDD compensation curve. Experimental results show the pulse width of sample position is Octreased averagely 95 fs after dispersion compensation,and that fluorescence intensity of biological sample is increased respectively by 42. 7% and 76. 8% in two typical excitation wavelengths( 700 nm and 900 nm). In conlusion,two-photon excitation efficiency and the pulse width of femtosecond laser is the linear inverse relationship.