Synchro-Excited Free-Running Single Photon Counting: A Novel Method for Measuring Short-Wave Infrared Emission Kinetics
Synchro-Excited Free-Running Single Photon Counting: A Novel Method for Measuring Short-Wave Infrared Emission Kinetics
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同步激发自由运行单光子计数：一种测量短波红外发射动力学的新方法
DOI：
10.1021/acs.analchem.9b03207
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发表时间：
2019
影响因子：
7.4
通讯作者：
Weisman, R. Bruce
中科院分区：
文献类型：
--
作者：
Lin, Ching-Wei;Bachilo, Sergei M.;Weisman, R. Bruce
在涉及单线态氧、单壁碳纳米管和其他弱、慢发射样品的物理和化学研究中，需要在亚微秒到毫秒尺度上对短波红外（SWIR）光致发光进行时间分辨测量。我们在这里提出了一种替代时间相关单光子计数（TCSPC）的常用方法，该方法非常适合于在盖革模式下工作的砷化铟镓雪崩光电二极管（APD）探测器。在这种被称为同步激发自由运行单光子计数（SEFR-SPC）的新方法中，来自廉价激光二极管（提供各种波长）的激发脉冲与覆盖900至1700 nm范围的自由运行探测器的检测事件同步。与传统的TCSPC相比，该方法的数据可以严格校正堆积畸变，从而实现高激励功率和低重复率的操作。描述了一种将系统的动态范围扩展到大约108的技术。我们还表明，SEFR-SPC在SWIR光谱区域提供了最先进的灵敏度，光谱过滤的动力学数据可以提供额外的见解。一个六步校正协议已经开发和实现作为一个LabVIEW程序非常准确的获取动力学形状。SEFR-SPC方法将成为研究弱、长寿命排放源的一个有价值的工具。
Time-resolved measurements of short-wave infrared (SWIR) photoluminescence on the submicrosecond to millisecond scale are needed for physical and chemical studies involving singlet oxygen, single-walled carbon nanotubes, and other samples with weak, slow emission. We present here an alternative to the common method of time-correlated single photon counting (TCSPC) that is well suited to indium gallium arsenide avalanche photodiode (APD) detectors operated in Geiger mode. In the new method, termed synchro-excited free-running single photon counting (SEFR-SPC), excitation pulses from inexpensive laser diodes (providing a variety of wavelengths) are synchronized to detection events from a free-running detector covering the 900 to 1700 nm range. In contrast to traditional TCSPC, data from this method can be rigorously corrected for pile-up distortions, allowing operation with high excitation powers and low repetition rates. A technique is described to extend the system’s dynamic range to approximately 108. We also show that SEFR-SPC provides state-of-the-art sensitivity in the SWIR spectral region and that spectrally filtered kinetic data can offer additional insights. A six-step correction protocol has been developed and implemented as a LabVIEW program for very accurate acquisition of kinetic shapes. The SEFR-SPC method will be a valuable tool for studies of weak, long-lived emission sources.