Analysis of influence factors of negative refraction phenomenon in particulate composite

The effective optical constants that describe the interaction between electromagnetic wave and particulate composite are calculated based on effective medium theory and Mie theory. The negative refractive phenomenon is compared between the Ge-particle-dispersed LiTaO₃ composites and Ag-particle-dispersed LiTaO₃ composites. It is indicated that the negative refraction phenomenon for semiconductor Ge particulate composite occurs in higher frequency range than that of noble Ag particulate composite. By take the Ge particulate composite as an example, the influence of size and number density of spherical particles on the negative refraction phenomenon is analyzed. It is indicated that the frequency range where negative refraction phenomenon occurs can be shifted to higher frequency by adjusting these two influencing factors.