Fabry-Perot cavity filter based on lithium niobate

An optical filter based on lithium-niobate-on-insulator using a Fabry-Parot cavity with multimode waveguide gratings. The fabricated device with a length of $\sim 60 \mu \mathrm{m}$ and a large Free Spectral Range (FSR), most considerable FSR of $\sim 22 \mathrm{nm}$.