Optical Transmission Characteristics Of Photonic Crystal Research

Recently, photonic crystal has become one of the focuses of researchers all over the world. The paper is about the three aspects followed: abnormal refraction of photonic crystal, photonic crystal containing negative refraction materials, and photonic crystal fibers.1. With plane wave method, the relation between the incident angle and refraction angle and frequency in one-dimensional photonic crystals are investigated. It is found, when frequency is near the edge of band and incident angle is near the sensitive domain, the varition of refracton angle is sensitive;while frequency increase, the sensitive domain moves to small angles.2. By "means of transfer matrix method, the transmission properties of one-dimensional photonic crystals containing negative refraction materials (with a defect layer in it) were investigated. The transmittance were calculated, which include two kinds of conditions: normal dielectric layer and absorbing dielectric layer. It is shown that, on normal incidence, for the normal dielectric layer, the number of the defect modes increase with the increase of width of the layer;for the absorbing dielectric layer, with the increase of width and absorbing of layer, the defect mode will not emerge, instead, the peak of transmission were increased.3. Using the results of printed papers, the trend of the dispersion with different structures is analyzed. Based on scalar approximation the dispersion property of photonic crystal fibers are investigated by an effective index approach in this paper. It is found that the photonic crystal fiber with closing to zero and flattened chromatic dispersion is obtained by changing the core diameter independently. Which has absolute value less than 1.5 ps ? km^-1 ? nm^-1 in dispersion coefficient D at the wavelengths from 1.3μ m to 2.0 μm.