In every switching node, optical signals are converted to electrical form (O/E conversion), buffered electronically, and subsequently forwarded to their next hop after being converted to optical form again (E/O conversion). switching with no moving parts) can use devices based upon electro-optic materials such as lithium niobate (LiNbO 3). An electro-optic material is one whose refractive index changes significantly when an electric field is applied across it. Figure 23 shows a 2 ×. While traditional electrical switches handle 90% of household circuits, they become bottlenecks in modern optical networks. The global optical switch market reached $5.