基于透镜成像系统对微小透明物体的测量方法

摘要

生活中有许多微小透明物体,当光通过它们时,因为其折射率与周围空间不同而产生相位差,但不会产生振幅差,无法被人眼和普通显微镜观测.实验中提出一种利用透镜成像滤波系统实现对微小透明物体观察并测量其大小的方法.当高斯连续激光作用在吸收溶液上时,溶液会吸收激光中部分能量,产生热透镜效应.利用此效应,使吸收溶液能够模拟传统昂贵的相位滤波器,对透过相位物体的光线进行调制,将人眼无法观测到的相位变化转化为可被 CCD接收的光强变化,从而实现对微小透明物体的观察及测量.选取已知大小的透明 SiO2薄片作为待测样品,实验结果表明测量值与样品实际大小非常接近.%There are many tiny transparent obj ects in life.When the light passes through the tiny transparent obj ects,the obj ects cannot be observed by the eye and common microscope, because the difference of refractive index of the transparent obj ects and the surrounding can only make phase difference but no amplitude difference.In the experiment,a method of ob-serving and measuring the size of a tiny transparent obj ect by means of a lens imaging filter system is proposed.When Gauss continuous laser is applied to the absorption solution,the solution absorbs part of the energy of the laser and produces a thermal lens effect.With this thermal lens effect,the absorption solution can simulate the traditional expensive phase filter and modulate the light through phase obj ect.It transform the phase difference,which eyes cannot observe,into the change of light intensity,which can be received by CCD,so as to re-alize the observation and measurement of tiny transparent obj ects.Taking the transparent SiO2sheet,whose radius is known,as a sample to be tested,the experimental result shows that the measured value is very close to the actual size of the sample.