摘要
提出一种对光源输出功率稳定度要求相对较低的激光全息防伪产品光学特性参数检测方法。使用一块透反比一定的玻璃基片,将相对不稳定度3%的 He-Ne 激光器输出光束分为两束:反射光和透射光。两束光光强度比例恒定,测量反射光强计算出透射光强度。透射光作为再现光照明激光全息防伪标识,其衍射光构成物体再现像。实时探测标识光栅处以及无光栅处的衍射光强与反射光强,进而得到光栅处衍射光强与再现光强的比值及其与无光栅处衍射光强的比值,即全息防伪标识的衍射效率和信噪比。实验结果表明:透射光强测量值相对误差不超过0.2%;衍射效率及信噪比的测量值相对误差分别不超过0.8%和1.9%。
In this paper,a new method is presented,with relatively less dependency on the stability of source light,to measure the diffraction efficiency and SNR of the laser holographic anti-counterfeiting labels.The He-Ne laser,having 3% relative instability,is used as the light source.A piece of glass divides the source light into two beams at a fixed ratio,the reflex and the transmission.The reflex is utilized to calculate the intensity of the transmission due to the fixed ratio.The transmission as the reconstructing light illuminates the holographic label,and produces diffraction image.The intensities of the reflex and the diffraction are collected in real time,when the reconstructing light illuminates the grating and the point with no grating on the label.According to the collected data, the ratios of the diffraction intensity from the grating to that from the no grating point and to the reconstructing light intensity are worked out.The experimental results show that the relative error of the transmission intensity is not more than 0.2%,that of the diffraction efficiency is not more than 0.8%,and that of SNR is less than 1.9%.
出处
《红外与激光工程》
EI
CSCD
北大核心
2006年第z3期379-384,共6页
Infrared and Laser Engineering
关键词
全息防伪
稳定度
衍射效率
信噪比
反射光
透射光
Holographic anti-counterfeiting
Stabilization
Diffraction efficiency
SNR
Reflex
Transmission
