Study On Abnormal Force In Optical Tweezers

In optical tweezers and other technologies,the manipulation of particles using the optical force of the interaction between light and matter has been extensively studied in theory and experiment.Because the manipulation method of optical tweezers is noninvasive and non-invasive,it has been widely used in the fields of biology,medicine and medical detection.In general capturing optical tweezers,the light field will push the micro-nano particles in the direction of light propagation on the illuminated area,or use the field strength gradient to capture the micro-nano particles.Such radiation pressure and gradient force are clearly observable.In recent years,the abnormal stress phenomenon in optical tweezers technology has attracted wide attention due to its novel stress phenomenon.The abnormal force in these optical tweezers technology brings a new degree of freedom to traditional optical manipulation and provides a reliable solution for particle screening.The main subject studied in this paper is the lateral force effect in the abnormal force of optical tweezers.The anomaly is reflected in the direction of the wave vector of the incident light and the direction of the force of the micro-nano particles.The force will also be completely reversed.In the current study of the lateral force effect,the lateral force effect is not obvious compared to the radiation pressure,and the model is difficult to achieve in experiments.First of all,this subject investigates the recent research results of abnormal forces in optical tweezers.This subject will realize the enhancement of the lateral force effect,so that the lateral force can be used as a particle screening tool as a scientific research goal.Aiming at the lateral force effect caused by SPP,this topic first analyzes the generation mechanism of SPP and the force mechanism in SPP optical tweezers,which lays a physical foundation for the lateral force analysis in subsequent chapters.Later,the lateral force effect model of two incident light beams with spin interference when irradiated on an achiral particle was analyzed.The lateral force effect of the two-beam circularly polarized interference field was more obvious than the previous single beam model Because of the uniqueness of its force direction,it has greater application value in the future screening work;at the same time,the influence of the parameters of the incident light source,particle size and other parameters on the lateral force is explored,and the strongest lateral force effect is determined.A set of parameters.Secondly,this subject has designed two methods of generating abnormal stress and enhancement only by a single beam vector light source.One type of CVB beam is generated by the superposition of x and y polarization,and the other type of CVB beam is caused by radial polarization.The superposition with angular polarization is generated,and the force of the particles in the light field is analyzed.It provides new basic support for the screening of particles and cells in the future.Finally,the lateral force model designed by this subject is summarized,the follow-up research plan of this subject is elaborated,and the application of this model in future experiments is prospected.