Nonlinear optical decoder based on photonic quasi crystal ring resonator structure

Using two nonlinear photonic crystal ring resonators we proposed and designed an all optical decoder. 2D 12 fold quasicrystal was used as the core section of the resonant rings. In order to make use of advantages of nonlinear Kerr effect, we put 24 dielectric rods between the core and outer shell of the resonant ring. The linear refractive index and nonlinear Kerr coefficient of these rods are n 0 = 1.4 and n 2 = 10−14 m2/W. In the proposed structure port I was used to switch the optical beams coming from BIAS between O1 and O2 output ports. The optical intensity required for performing the switching task is about 0.1 kW/μm2.

Application of photonic crystal based nonlinear ring resonators for realizing all optical 3-to-8 decoder

Optical decoders are required for optical routing. In this paper we presented the design procedure and simulation results for 3-to-8 optical decoder, which was designed using nonlinear ring resonators inside two dimensional photonic crystals. The proposed structure was simulated using finite difference time domain method. Based on the simulation results the maximum delay time of the structure is about 2 ps. Also the worst transmission values for logic 0 and 1 are 10% and 78%, respectively.

Improving the Performance of 2-To-4 Optical Decoders Based on Photonic Crystal Structures

In this study, a novel, two-dimensional photonic crystal-based structure for the 2-to-4 optical decoder is presented. The structure consists of 23 rows and 14 columns of chalcogenide rods that are arranged in a square lattice with a spatial periodicity of 530 nm. The bias and the optical signals are guided toward the main waveguide through the three waveguides. Two unequal powers are applied to the input ports to approach the different intensities proportional to four working states into the main waveguide. Four cavities including the nonlinear rods are in response to drop the optical waves toward the output ports. To calculate the band diagram and the spatial distribution of the electric and magnetic fields, the plane wave expansion and the finite difference time domain methods have been used. The delay time of the designed structure is obtained around 220 fs, which is less than one for the previous structures. Furthermore, the gap between the margins for logic 0 and 1 is equal to 83%, which is higher than one for other works. Besides, the area of the structure is reduced to 90 µm2 in comparison to all reported structures. Based on the mentioned results, it seems that an improvement of the performance for 2-to-4 optical decoders has been obtained in this research.