Abstract:Broadband optical switches are required for a wavelength division multiplexed photonic network node. The wavelength dependency of the LiNbO 3 optical switch characteristics are mainly attributed to the directional coupler section. An asymmetric X-junction was suitable for a broadband optical switch because it has flat spectral response over wide wavelength range and it is easy to fabricate. We have optimized the structure of an asymmetric X-junction and fabricated the 1×2 LiNbO 3 optical switches using it. The optical switch showed broad band characteristics compared to the switch with a directional coupler.