Low V π L electro-optic switch based on a densely packed waveguide array phase shifter

Lithium niobate on insulator and lithium tantalate on insulator are promising platforms for electro-optic (EO) switches. However, compact devices with low half-wave voltage-length products ( V π L ) remain challenging, limiting high-density integration. Here, we propose and experimentally demonstrate a low- V π L EO switch on x-cut LTOI based on a densely packed waveguide array (DPWA) phase shifter. The device achieves a measured V π L of 1.49 V·cm, close to the simulated 1.20 V·cm, while maintaining low insertion loss over 1520–1580 nm.