基于荧光时间分辨相图分析的人民币鉴伪技术

RMB identification using the polar phasor approach on the time-resolved fluorescence

人民币鉴伪技术的关键之一是造币用纸的检测.本文提出了测量人民币用纸荧光时间分辨过程的鉴伪新方法,采用了双光子共焦扫描荧光时间分辨显微成像的实验方案,提出了极坐标相图分析法,测量和分析了人民币真钞和伪钞用纸的平均荧光寿命.人民币真钞用纸的荧光时间分辨过程符合双指数衰减模型,各种面值人民币的平均荧光寿命相差不大,但是伪钞的平均荧光寿命与真钞的相差明显.实验结果证明基于荧光时间分辨过程极坐标相图分析的人民币鉴伪技术不受钞票的新旧程度、机械皱褶、损伤和表面污染物的影响,其测量方法灵敏、实用,检测装置可靠,能够有效地鉴别出人民币的真伪.

One of the key technologies to identify RMB banknotes is to detect its paper tissue. In this paper, using two-photon fluorescence confocal microscopy, a new RMB identification technology based on the polar phasor approach of the fluorescence lifetime is put forwards. This is the first time that the polar phasor approach has been applied to analyze the average fluorescence lifetime of the genuine and counterfeit RMB banknotes, respectively. The time-resolved fluorescence process of the genuine banknote conforms to the double-exponential decay model. There are almost no differences among the average fluorescence lifetimes of the various denominations of RMB genuine banknotes; however, the difference of the average fluorescence lifetimes between the genuine and counterfeit banknotes is significant. The experimental results show that the RMB identification technology cannot be affected by the circulation time, mechanical crease, injury, and surface pollutant on the banknotes. The measurement method is sensitive, and the device is reliable; therefore, it can identify the RMB genuine and counterfeit banknotes effectively and practically.