Tunable optical filter with high performance based on 2D photonic crystal

In this paper, we investigate the performance of a new form of photonic crystal filter. The proposed filter consists of two waveguides and a resonator whose resonator section consists of a rectangular defect and two rods with different radii and refractive index. The structure consists of a two-dimensional square lattice with circular dielectric rods in the air bed. The final dimension of this filter is 60.86 μm2. The photonic crystal band structure calculations are performed using the plane wave expansion method. The finite difference time domain is used to propagate the electromagnetic field in the filter and plot the corresponding transmission spectra. The transmission efficiency, bandwidth, and quality factor at the resonant wavelength 1582.2955nm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1582.2955\, \textrm{nm}$$\end{document} are equal to 93.6%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$93.6\%$$\end{document}, 0.077nm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$0.077\, \textrm{nm}$$\end{document}, and 20549.3, respectively. Also, the effect of different parameters on the wavelength selection behavior of the proposed filter is studied. The simplicity of design and integration capability is important features of this filter, and this feature makes this design suitable for optical telecommunication applications.