Reflective Grating Array Based Delay Lines in Thin Film Lithium Niobate on Insulator

This work demonstrates delay lines using reflective grating arrays formed through etched grooves in thin film lithium niobate on insulator. SH0 modes are launched and received through a reflector array in this material stack for the first time. The reflection coefficient for etched grooves is determined through simulation and grating arrays are demonstrated experimentally for h/λ ratios of 5×10
⁻³
and 10
⁻²
at a center frequency of 455 MHz in conventional and linearly chirped grating arrays. This forms a first step towards future implementation of large time bandwidth product delay lines for analog signal processing.