Design and fabrication of lithium niobate based single mode Y-branch APE waveguide

In this paper, we report on a minized length, compact, low loss Y-branch waveguide based on lithium niobate optical crystal. The Y-branch waveguide device was fabricated using annealed proton exchange technique to achieve single mode guiding at 1550 nm wavelength. The simplified Y-branch structure has a total length of 18.7 mm and calculated bending loss of 0.5 dB has been realized with a splitting ratio found to be 1.25 at 1550 nm wavelength. Such easy to fabricate waveguide could find applications in future photonic communication networks, sensing, and quantum information technology.