Observation of time-dependent luminescence from excited states with a wide range of lifetimes allows students to explore the connection between selection rules and transition rates. It is fairly simple to measure microsecond and longer lifetimes with equipment common to undergraduate programs, because the instrument response time of even modest bandwidth systems is insignificant on microsecond and longer time scales. The measurement of nanosecond lifetimes, however, is more challenging, because the instrument response time is comparable to the lifetimes being measured. In this case, the instrument temporal response must be deconvolved from the observed luminescence signals in order to extract the actual excited state lifetime. We describe a method for measuring nanosecond fluorescence lifetimes in the advanced undergraduate laboratory that uses real-time analog luminescence signals instead of traditional photon counting techniques. The detection electronics of this method are fairly simple, consisting of an oscilloscope monitoring the time-dependent output of an inexpensive silicon photomultiplier. We introduce a simple and transparent method for students to characterize the instrument response and deconvolve it from the observed luminescence signals, yielding measured nanosecond fluorescence lifetimes in good agreement with the corresponding literature values obtained by time-correlated single photon counting. The limitations of silicon photomultipliers for this method of measuring nanosecond lifetimes are discussed in detail. Application of this treatment to decay processes that are not single exponential is also discussed.

中文翻译：

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在高级本科实验室中对仪器时间响应进行简单校正的荧光寿命测量

观察具有广泛寿命的激发态随时间变化的发光，使学生能够探索选择规则和跃迁率之间的联系。使用本科课程常用的设备测量微秒和更长的寿命相当简单，因为即使是中等带宽系统的仪器响应时间在微秒和更长的时间尺度上也无关紧要。然而，纳秒寿命的测量更具挑战性，因为仪器响应时间与被测量的寿命相当。在这种情况下，仪器时间响应必须从观察到的发光信号中解卷积，以提取实际的激发态寿命。我们描述了一种在高级本科实验室中测量纳秒荧光寿命的方法，该方法使用实时模拟发光信号而不是传统的光子计数技术。这种方法的检测电子设备相当简单，由一个示波器组成，用于监测廉价的硅光电倍增管的时间相关输出。我们为学生介绍了一种简单透明的方法来表征仪器响应并将其从观察到的发光信号中解卷积，从而产生与通过时间相关的单光子计数获得的相应文献值非常一致的测量纳秒荧光寿命。详细讨论了这种测量纳秒寿命方法的硅光电倍增管的局限性。