Measuring two-photon microscopy ultrafast laser pulse duration at the sample plane using time-correlated single-photon counting.
Measuring two-photon microscopy ultrafast laser pulse duration at the sample plane using time-correlated single-photon counting.
复制标题
使用时间相关的单光子计数测量样品平面上的双光子显微镜超快激光脉冲持续时间。
DOI：
10.1117/1.jbo.25.1.014516
复制
发表时间：
2020
影响因子：
3.5
通讯作者：
Vogel,StevenS
中科院分区：
文献类型：
--
作者：
Kim,Youngchan;Vogel,StevenS
双光子显微镜（2PM）通过允许在相对较厚的生物标本中进行薄的光学切片而彻底改变了生物医学成像。由于2PM中的色散显微镜组件，例如物镜透镜，可以改变时间激光脉冲宽度（通常在样品平面处更宽），为了精确测量双光子吸收特性，重要的是表征样品平面处的脉冲持续时间。我们提出了一个简单的修改双光子显微镜的光路，允许二次谐波产生为基础的干涉自相关测量的特征超快激光脉冲的持续时间在样品平面使用时间相关单光子计数（TCSPC）。我们表明，TCSPC可以作为一种简单而通用的方法来估计两个相邻的超快激光脉冲之间的零时间延迟步长值，这些测量。为了证明这种修改的实用性，我们使用10 × 10 - 2 mm的激光器在样品平面处测量了相干变色龙-超II钛：蓝宝石激光脉冲宽度。 空气，40 × 空气，或63 × 水浸物镜透镜。在950 nm双光子激发下，测得的脉冲宽度分别为154 ± 32、165 ± 13和218 ± 27 fs（n= 6，平均值±标准差）。
Two-photon microscopy (2PM) has revolutionized biomedical imaging by allowing thin optical sectioning in relatively thick biological specimens. Because dispersive microscope components in 2PM, such as objective lens, can alter temporal laser pulse width (typically being broader at the sample plane), for accurate measurements of two-photon absorption properties, it is important to characterize pulse duration at the sample plane. We present a simple modification to a two-photon microscope light path that allows for second-harmonic-generation-based interferometric autocorrelation measurements to characterize ultrafast laser pulse duration at the sample plane using time-correlated single-photon counting (TCSPC). We show that TCSPC can be used as a simple and versatile method to estimate the zero time delay step value between two adjacent ultrafast laser pulses for these measurements. To demonstrate the utility of this modification, we measured the Coherent Chameleon-Ultra II Ti:sapphire laser pulse width at the sample plane using a 10 × air, 40 × air, or 63 × water-immersion objective lens. At 950-nm two-photon excitation, the measured pulse width was 154 ± 32, 165 ± 13, and 218 ± 27 fs (n= 6, mean ± standard deviation), respectively.