The specification and drawings present a new apparatus and method for joining a window assembly (e.g., a glass window assembly) in electronic devices using optical/laser welding. A window assembly, transparent to an optical beam, may comprise an optical window such as glass window with a laminated layer (e.g., made of plastic) glued to a backside of the optical window and a back print ink layer between portions of the optical window and of the laminated layer. This window assembly may be attached to a frame such as a plastic frame, non-transparent to the optical beam, having at least one boundary with the laminated plastic layer of the window assembly using a welding joint at the at least one boundary made by the optical beam propagating transparently (with negligible optical absorption) through the window assembly and absorbed by the plastic frame.