Fig. 2: Photonic design of the Pb2+ ion sensor.
From: Crown ether decorated silicon photonics for safeguarding against lead poisoning
a Simulation of the number of supported TE optical modes in the slot waveguides as a function of strip and slot width. b Sensor surface sensing FoM as a function of strip and slot width. c The comparison of two proposed splitting Mach-Zehnder architectures (see Supplementary Note 5) in terms of the power asymmetry required of the splitter; condition 1 (\({{{{{{\rm{S}}}}}}}_{1}={{{{{{\rm{S}}}}}}}_{2},{{{{{{\rm{S}}}}}}}_{1}^{{\prime} }={{{{{{\rm{S}}}}}}}_{2}^{{\prime} },{{{{{{\rm{S}}}}}}}_{1/2}^{{\prime} }\ne 0.5\)), condition 2 (\({{{{{{\rm{S}}}}}}}_{1}^{{\prime} }\ne 0.5,{{{{{{\rm{S}}}}}}}_{2}^{{\prime} }=0.5\)). Top-down electric field distribution of the d, asymmetrical adiabatic tapered splitter, and e, adiabatic strip-slot converter, where the structures of the components are outlined.
