Lithium niobate ($\mathrm{LiNb}{\mathrm{O}}_3$)

Lithium niobate is $\mathrm{LiNb}{\mathrm{O}}_3$, a crystalline oxide containing lithium, niobium, and oxygen. Its non-centrosymmetric structure supports piezoelectricity and useful optical responses.

An applied electric field can change its optical response, allowing electrical control of light in a modulator. The connection between crystal symmetry and macroscopic response makes lithium niobate a bridge between crystallography and optical engineering.