Recognizing The Micro-objects Using The Rotating Polarized Light

There are some special superiorities using light scattering method to distinguish small objects,especially the things smaller than the 1 ?m.When the detection things become smaller and smaller,it will be difficult to distinguish things using image method directly,and there are some advantages for using the light scattering technique in this case.Using the light scattering technique,extracting some polarized characteristic numbers,and calculating Mueller matrices,then to distinguish micro things and small algae.The thesis mainly introduce a method that using light polarized scattering technique to detect the small things and small algae,using the rotated polarized light to distinguish the detecting objects.When the light irritate the small things,basing on the Rayleigh electric dipole radiation theory,inside the small particles will induce a dipole moment,the dipole moment will oscillate when the oscillating light irritate,then will radiate the electromagnetic wave.We put the detector at multi-angles,and there are four channel at each angle.These four channels are wave plate with fast axis along the 45 degree angles add the 0 degree angles polarizer,45 degree angles polarizer,90 degree angles polarizer,135 degree angles polarizer.In this thesis,we will see there are some similar rules in each channel light intensity,alone with the direction changing of the incident light,according to the theoretical calculation,the light intensity through each channel is function of the direction of incident ligh t.There are three parameters in this function,this thesis will introduce these three parameters in detail,especially the phase parameters.We will focus on the simple micro balance objects,for example,the polystyrene spheres.In the experiment,we found the phase will change for different diameter polystyrene spheres for the 135 degree polarizer in the 60 degree detecting angle,we will recognize the different diameter polystyrene spheres preliminarily from the change of the phase.The experiment also found that the phase won't change if changing the color of the sphere,the rotating speed of the magnetic stirrer,and the concentration of the experimental solution.The experiment analyzed the parameter A,B for different concentration.The thesis calculate Mueller matrices and the degree of polarization using the basic knowledge of polarized light.In this thesis,studying on the simple objects and then to the complicated objects.In this thesis the main innovation is the experimental curves are familiar with each other for different solutions,and using the dipole radiation theory and the hypothesis to explain the experimental phenomenon,and giv ing the simulation function,and finding that the phase will change for different diameter polystyrene spheres.