激光诱导叶绿素荧光强度与激光强度关系

为满足激光诱导叶绿素荧光无损检测技术的发展需要，该文利用反射式激光诱导叶绿素荧光光谱分析技术对黄瓜活体叶片的叶绿素荧光强度与激发光强度关系进行试验研究。通过中心波长为473和660 nm 2种激发光的4种激发强度（2.50、5.00、7.50、10.00 mW）对具有不同生理信息（叶绿素含量、叶片含水率）的黄瓜活体叶片进行荧光激发，并利用MATLAB软件对685 nm和732 nm两个峰位的荧光强度进行分析。结果显示：各峰位荧光强度与激发光强度成极显著线性关系；叶片叶绿素含量对荧光强度与激光强度关系影响显著，各峰位荧光变化梯度与叶绿素含量具有较好的线性关系，但叶片含水率却影响不大；以此研究为基础，建立了具有叶绿素含量参数的荧光强度与激发光强度关系数学模型，模型相对预测误差小于0.2%，可靠性好，能较真实准确地反映荧光强度与激发光强度的关系。

Relationship between laser-induced chlorophyll fluorescence intensity and laser power

In order to meet the needs of developing laser-induced fluorescence (LIF) non-destructive detecting technique, the relationship between chlorophyll fluorescence intensity of cucumber leaf in vivo and laser power was studied by reflectance laser-induced fluorescence (LIF) spectrum analysis technique in this paper. Fluorescence spectrums, which were induced by four kinds of laser power (2.50, 5.00, 7.50, 10.00 mW) of two kinds of center wavelength 473 and 660 nm, respectively, were analyzed in the experiment. Under those conditions, fluorescence intensities of center wavelength 685 and 732 nm for different plant physiology information (chlorophyll content, water content) were calculated and analyzed by MATLAB software. The results showed that there was a very significant linear correlation between fluorescence intensity of each peak position and laser power; chlorophyll content impacted on the relationship between fluorescence intensity and laser power significantly, and a linear correlation between fluorescence intensity gradient of each peak position and chlorophyll content was found. However, that relation insignificantly correlated with water content. Based on those results a mathematical model with chlorophyll content parameter of relationship between fluorescence intensity and laser power was established. The relative square error of prediction of the model was less than 0.2%, and it exactly reflected the relationship between chlorophyll fluorescence intensity and laser power.