Design and simulation of optical filter based on photonic crystals

Abstract

With the ever-increasing volume of information sent and the increase of users of the telecommunication network, electrical systems have lost their efficiency and are replaced by optical systems that are faster and safer. To increase the efficiency of optical systems, all devices must be designed optically. . A great option for designing optical devices is to use optical crystals. Optical crystals are materials with an alternating dielectric coefficient, which have a range in their structure called the optical crystal band gap, through which no wavelength passes. However, by creating defects in the network of these crystals, some wavelengths can be allowed to pass through their band gap. And this has made optical crystals to be a very suitable solution for making optical devices. Optical filters are the key members of optical communication systems that are used as multiplexers and demultiplexers in these systems. Our goal in this article is to introduce optical crystals and their use in the design of optical filters used in telecommunication systems. In this article, a connected structure for designing an optical filter based on photonic crystal is proposed. The designed filter has the ability to select signals with a wavelength of mn 1550 and the overall footprint is less than 118 μm^2. The transmission coefficient and bandwidth obtained are equal to 92% and mn 0.9 respectively. After designing the filter, the effect of different parameters on the behavior of the filter has been investigated. Simple design and very small dimensions are the most important features of this filter.