4. Outlook

This article focuses on electro-optical modulators based on two types of material: lithium niobate and polymers. Lithium niobate-based devices are in full technological maturity, while polymer-based devices have struggled to make the breakthrough despite their good performance, partly because of persistent doubts about their long-term stability and partly because of insufficient technological maturity.

The superiority of polymers lies not only in the possibility of lower control voltages, or a much higher bandwidth than niobate. They are also easy to produce, can be manufactured in large quantities and at low cost using molding methods, and can form multilayer structures enabling vertical integration. On the other hand, the compatibility of polymers with inorganic or semiconductor materials such as silicon means that hybrid devices can be developed, combining the...