Design and fabrication of wide-angle abrupt bends on lithium niobate

A new wide-angle low-loss abrupt bend is presented. A prism-like region of index equal to that of the substrate is placed at the bend corner to compensate the phase mismatch caused by the bend. The novel abrupt bend has been fabricated on a LiNbO/sub 3/ substrate by proton exchange. The experimental result shows that the normalized transmitted power is 63% with a bend angle of 10/spl deg/, which is quite close to the simulated result.