Size Effect Of Optical Constant Of Particle

There are a lot of particles in aerospace, meteorology, construction, medical, and other various applications. In studying the characteristics of electromagnetic radiation particle theory, the particle nature of the index of refraction is the prerequisite and basis for the particle radiation. We can not ignore the changes which bring to the optical constants when particle size is compared with the optical wavelength. Currently, the index of refraction of some material particles is displaced by either the value of bulk material or measurements value which is limited by a certain size and wavelength.This paper has studied the size effect of particles for the optical constants value in theory. Through Lorentz and Drude dispersive theory, we tried to analyzed the parameters which may cause the size effect of n and k value. We bring in size parameter into relaxation time of free electron on basis of Drude model, and build a metal particle n and k model which vary with size and wavelength. On basis of Lorentz model, we bring in size parameter into bound electron relaxation time and plasma frequency by analogy with phonon scattering, and build a dielectric particle n and k model which vary with size and wavelength.We analyzed the calculated n and k value of alumina oxide particles from the size, wavelength, and temperature, conclude that when particle size is compared with the optical wavelength the model can calculate the particle values of optical constants n and k . The calculation value is consistent with the experiment value of bulk at the 0.6328μm wavelength. The calculate value of diameter 0.97μm changing with the wavelength consistent with Brewster calculated value and experimental values of bulk, the calculate n value is bigger than others, the calculate k value is smaller than others. The calculated n and k value of different temperature changing with wavelength compare with Brewster value, conclude that the value of particle is consistent with the law of bulk. At the same time, we also calculated n and k value of gold nano-particles, which reflects the size effect of n and k value when gold particles diameter is different. The size effect model of dielectric particle and metal...