title: Mode switch based on electro-optic long-period waveguide grating in lithium niobate.
abstract: We propose a mode switch based on an electro-optic long-period grating formed in a lithium-niobate (LN) two-mode waveguide. Our fabricated device consists of an 8 mm long grating in a proton-exchanged z-cut LN waveguide. At a driving voltage of 35 V, it can switch between the fundamental mode and the higher-order mode with a mode extinction ratio of -18  dB and a 3-dB bandwidth of ∼25  nm at the wavelength 1544 nm. The performance of the device is insensitive to temperature variations. The experimental results agree well with the simulation. This mode switch could find applications in reconfigurable mode-division-multiplexing systems.
authors: Wei
authors: W
authors: Jin
authors: Kin Seng
authors: KS
authors: Chiang