Enhanced polarization-independent two-layer five-port grating with covering layer

Abstract

In this paper, an enhanced polarization-independent two-layer five-port grating with covering layer is proposed. The rigorous coupled-wave analysis (RCWA) is used to predict grating parameters. In addition, the total efficiency of the polarization-independent five-port grating with covering layer can exceed 80% with the good uniformity of 1.97% for TE and TM polarization. The inherent coupling mechanism and the electric field energy distribution of the gratings are explained well under TE and TM polarization by the simplified mode method (SMM) and the finite element method (FEM). According to the reported five-port gratings, the proposed transmission five-port grating with a covering layer has good uniformity for TE and TM polarization. Moreover, the grating can be protected and the groove of the grating can be kept clean by adding a covering layer during the actual fabrication. At the same time, the fabrication errors of the two-layer five-port diffraction grating are further considered. Therefore, the numerically simulated five-port grating with covering layer has a wide application prospect in precision displacement measurement and holographic projection imaging.

Structure and characterization of plus-shaped configuration for 1 × 4 splitter

“…Gong et al. presented a five-port beam splitter and explored the diffraction characteristics in the near infrared region through the modal method (MM) and rigorous coupled-wave analysis (RCWA) 21 . Lin et al.…”

“…20 Gong et al presented a five-port beam splitter and explored the diffraction characteristics in the near infrared region through the modal method (MM) and rigorous coupled-wave analysis (RCWA). 21 Lin et al designed a grating with a cross-shaped ridge structure and investigated the transmittance feature in the near infrared region by RCWA and simplified MM. 22 Among them, the four-port diffraction gratings are widely used in many fields due to their good diffraction efficiency and flexibility.…”

Plus-shaped dielectric grating for seven-channel transmission

“…In recent years, many researchers have studied the multi-port output beam splitter. Based on the situation of the output light, multi-port grating beam splitter can be divided into reflective grating beam splitter and transmissive grating beam splitter [19][20][21][22][23][24]. Usually, the beam splitter with silver layer structure is reflective grating beam splitter and the light will be reflected back by the silver layer.…”