Figure 6
Conformal mapping processes for a beam splitter with three ports.
(a) Structure of the beam splitter. The three solid lines represent the three ports for input or output. (b) Splitter mapped onto the upper half-plane of the w-plane. (c) Final mapped structure of the splitter when the incoming beam is equally split into two beams. (d) The permittivity distribution and the curved coordinate grid in the splitter when it is mapped onto (c). (e) Final mapped structure of the splitter when the incoming beam is unequally split into two beams. (f) The permittivity distribution and the curved coordinate grid in the splitter when it is mapped onto e. The split ratio of port 2 to port 3 is 1/2.
