Study On The Propagation Property Of Gaussian Beams In Absorbing Metamaterials

Metamaterial is a kind of artificial composite construction novel material, then negative refractive index metamatrials have both negative permittivity and negative permeability. For its wave vector, electric field and magnetic field form a left-handed triplet of vectors and so such materials are called left-handed materials (LHMs). Also, the left-handed materials can be artificially tuned. Nowadays, NIM in the near IR and optical range have also been experimentally demonstrated. No matter the theoretic or empirical new development will be a revolutionary influence on the field of physics, electronics and communication. The main research and results of this paper are as below.Firstly, basing on the representation of plane-wave angular spectrum, we obtain paraxial rays and vertically incident Gaussian beams transport model. Additionally, we have discussed the energy transmission of Gaussian beams in absorbing metamaterials and the inherent physical mechanism.Secondly, starting from the representation of plane-wave angular spectrum, we construct the reflection transmission model of paraxial Gaussian beams in the interface between absorbing matematerials and normal materials. We have studied the oblique incidence Gaussian beam which is composed by the same frequency and different wave vector direction plane waves. Also, we have discussed the reflection angular shift at the interface between negative, near-zero and very large refractive index metamaterials and air. At the same time, we have analyzed transverse and longitudinal angular shifts at near-zero and very large refractive index and the relation-ship between the reflective beams angular shifts and the permittivity, permeability. Further more, we expound the reflection parameter effect on the reflection angular shifts. Finally, we found the law of metamaterials absorbing parameter controlling on angular shifts.Finally, we have researched the bending effect of oblique incident Gaussian beams in absorbing materials. On the one hand, we have demonstrated that when the electromagnetic wave incident into the absorbing left-handed material, there is an angle between the Poynting vector and the wave vector led by the absorbing factor which is different from the parallel two vectors in harmonious metamaterials without absorption. The angle between Poynting vector and the wave vector become larger with the increase of absorbing parameter. On the other hand, for the representation of plane-wave angular spectrum, the Gaussian beams constituted by the same frequency and different directional wave vector plane electromagnetic wave, the centroid will bend towards the transport axial, and the bending effect will become obvious with the increase of the absorbing parameter.