Laser processing of lithium niobate for wafer-level microfabrication applications

An investigation of the application of a frequency-tripled Nd:YAG laser to process lithium niobate (LiNbO3) wafers is presented. Laser dicing, drilling and contoured cutting are demonstrated. An assessment of the laser processing technique in terms of the machined quality, resolution and processing time is conducted. Minimal surface damage and debris, machined width of 30µm, through-wafer machining of LiNbO3 wafer with a thickness of 500µm, and short processing time have been achieved. The results show that laser processing can produce geometric features of a scale and complexity that are difficult to achieve with traditional mechanical machining, while also providing high speed fabrication that is not available with conventional photolithographic etching. The demonstrated technology has applications in the manufacturing of next generation photonics devices.