Tommasi Federico, Ignesti Emilio, Fini Lorenzo, Martelli Fabrizio, Cavalieri Stefano
Opt Express. 2018 Oct 15;26(21):27615-27627. doi: 10.1364/OE.26.027615.
Optical sensing is a very important method for investigating different kinds of samples. Recently, we proposed a new kind of optical sensor based on random lasing [ Sci. Rep.6, 35225 (2016)], that couples the advantages of stimulated emission in detecting small variations on scattering properties of a sensed material, to the needs of no alteration of the sample under investigation. Here, we present a method to achieve a quantitative measurement of the scattering properties of a material. The results on samples of calibrated microspheres show a dependence of the peak intensity of the emission spectrum on the transport mean free path of the light within the sample, whatever the dimension (down to ≈100 nm of particle diameter) and the concentration of scatterers dispersed in the sensed material. A direct and fast measurement of the scattering properties is obtained by calibration with a well-known and inexpensive reference medium.
光学传感是研究各类样品的一种非常重要的方法。最近，我们提出了一种基于随机激光的新型光学传感器[《科学报告》6, 35225 (2016)]，它将受激发射在检测被传感材料散射特性微小变化方面的优势，与不对被研究样品进行改变的需求相结合。在此，我们提出一种实现材料散射特性定量测量的方法。校准微球样品的结果表明，发射光谱的峰值强度与光在样品内的输运平均自由程有关，无论被传感材料中散射体的尺寸（低至粒径约100纳米）和浓度如何。通过用一种知名且廉价的参考介质进行校准，可直接快速测量散射特性。
