Excimer Laser Micromachining of LiNbO3 for Optical and Microwave Applications

In this paper, for the first time, excimer laser micromachining is applied to create new electro-optical devices called substrate integrated modulators, consisting of new optical and microwave waveguides on LiNbO3 substrates. The fact of having both optical and microwave waveguides, offers the possibilities to modulate high-frequency optical signal (wavelength of 1.55 mu m) by either millimeter or microwave signal (frequency of 60 GHz). Because LiNbO3 is transparent between 370 nm to 5000 nm, 248 nm KrF excimer laser is one of the best candidates for performing fine micromachining of this material. Cutting the LiNbO3 wafer, making holes, creating a ridge optical waveguide and fabricating a specific pattern of holes for microwave applications by 248 nm excimer laser are presented in this paper.