A reduced symmetric 2D photonic crystal cavity with wavelength tunability

Abstract

In this paper, we propose a microcavity supported by a designed photonic crystal structure that provides both tunability of cavity modes and the cavity's quality factor. A low symmetric defect region provides a trigger effect for the frequency shifting by means of rotational manipulation of small symmetry elements. Deviation of the effective tilling ratio as a result of rotational modification within the defect region results in the emanation of cavity modes at different frequencies. Here, we numerically demonstrate the frequency shifting for each obtained mode with respect to the defect region architecture. In addition to wavelength tunability, quality factor, mode volume, and Purcell factors are analyzed for the slightly modified structures. Besides, electric field distributions and polarization properties of each mode that emerge at distinct frequencies have been studied at adjusted frequency modes which are observed for all rotational modification scenarios as theta(Rot) = [0 degrees, 15 degrees, 30 degrees, 45 degrees]. After the investigations in 2D of silicon material (epsilon(r) = 12), 3D simulations are performed and the collected data is used for the height approximation of 3D structures to approach the results consistent with 2D ones, thus the cross-checking of the quality factor acquired from the 2D simulation can be executed by comparison with 3D. Moreover, 2D and 3D simulations of alumina material (epsilon(r) = 9.61) in terms of mode analysis and quality factor have been repeated considering the microwave experiments. Therefore, experimental analysis is compared with the numerical results and good agreement between the two is found.