Design of Tunable Wavelength Demultiplexer for DWDM Application Based on 1-D Photonic Crystal with KTP Defect

Abstract

We theoretically investigate the tunable wavelength selective filter by using one-dimensional photonic crystal (1D PC) with potassium titanyl phosphate (KTP) as a defect layer For this we study the transmission characteristic of the multilayered structure composed of (MgF 2 /ZnS) N (KTP)/(MgF 2 /ZnS) N . In order to get the transmittance spectra of defect PC we apply transfer matrix method (TMM). We use KTP crystal as defect layer because it is an electro-optical material and its refractive index changes with the change in the electric field intensity. Due to change in the refractive index, defect modes of the PC structure can be tuned at the desired wavelength. From the analysis of the transmittance spectra it is found that the average change in the central wavelength of defect mode is 0.6 nm/ 0.01 × 10 10 V/m. This property of tunable PC filter can be exploited in designing a wavelength demultiplexer for DWDM application in optical communication.