Design of \(2\times 4\) optical decoder based on IMI plasmonic waveguide with slot

To create compact, fast, and wide-band devices and break the diffraction limit, plasmonic technology has arisen. In this paper, the finite element method was employed in conjunction with the COMSOL version 5.5 software to present, investigate, and simulate the design of a \(2\times 4\) $2\times 4$ optical decoder. The optical decoder was manufactured using an insulator–metal–insulator waveguide with a slot and identical dimensions. Silver (Ag) is utilized as a conductor. Teflon was employed as the insulating material. When the structure was presented, its dimensions were (1090 \(\times\) $\times$ 400)nm. At an operating wavelength of 1550 nm, the transmission threshold ( \({T}_{\text{thr}}\) $T_{\text{thr}}$ ) value was determined to be 0.2. The efficacy of the design as presented was assessed using three criteria: modulation depth ( \(MD\) $\mathit{MD}$ ), contrast ratio ( \(CR\) $\mathit{CR}$ ), and insertion loss. The maximum \(MD\) $\mathit{MD}$ value is 99.96%, while the \(CR\) $\mathit{CR}$ achieves its zenith at 12.83 dB. The primary characteristic of the design demonstrated is its simplicity and compact size.