Streak camera has high temporal resolution and high sensitivity, and is a powerful tool in biomedical study to measure fluorescence lifetime and perform fluorescence lifetime imaging. However, nonuniformity of the gain in the streak tube and nonlinearity of the sweeping speed limit the precision of fluorescence lifetime measurement, particularly when fluorescence lifetimes are short. We have constructed a twophoton excitation fluorescence lifetime measurement system that is based on a synchroscan streak camera and have developed accordingly a method to correct the effect of gain nonuniformity and nonlinearity of sweeping speed on the measurement precision. A continuous-wave laser of high stability is used to calibrate the gain of the streak camera, and a Fabry-Perot etalon is used to calibrate the nonlinearity of the sweeping speed. Fitting algorithms are used to correct the gain of the streak camera and nonlinearity of the sweeping speed respectively, which significantly improves the measurement precision of the system, as characterized through the fluorescence lifetime of the short-lived fluorescence dye, Rose Bengal. Experimental results show that the measurement fluctuation of the lifetime has been improved from more than 10% to 2% after correcting the effects of gain nonuniformity and sweeping speed nonlinearity.
© 2010 Chinese Optics Letters
(170.0110) Medical optics and biotechnology : Imaging systems
(170.0180) Medical optics and biotechnology : Microscopy
(170.3880) Medical optics and biotechnology : Medical and biological imaging
(170.6920) Medical optics and biotechnology : Time-resolved imaging
(320.7080) Ultrafast optics : Ultrafast devices
Heng Li, Yonghong Shao, Yan Wang, Junle Qu, and Hanben Niu, "Improving the precision of fluorescence lifetime measurement using a streak camera," Chin. Opt. Lett. 8, 934-936 (2010)