Electrically Modulated Waveguide Grating on Thin-Film Lithium Niobate

Optical filters based on integrated phase-shifted Bragg gratings (PSBGs) have attracted considerable interest because they feature a Lorentzian-shaped resonance, along with strong out-of-band rejection across a broad stopband region. The extent of the stopband can be conveniently adjusted by modifying the grating coupling coefficient [1]. Fabricating PSBGs on a thin-film lithium niobate (TFLN) platform enables the selection and modulation of specific wavelengths at ultra-fast speeds [2]–[3], offering substantial advantages in applications like datacom, sensing, and microwave-photonics systems [4]. In this abstract, a monolithic PSBG based on TFLN is proposed. The low waveguide propagation losses combined with the strong grating coupling coefficient of these devices, enable a narrow wavelength selection combined with a large stopband and effective electro-optic tunning capabilities.