There are many of various ways to generate joints from flat pieces, and never all are restricted to laser cutters, but a lot of the procedures have over from fields like woodworking and metalworking. Mortise and tenon joints are similar to finger joints, besides the "fingers" on a single piece https://trumpf-laser-machine-pric36813.blogolenta.com/33830818/details-fiction-and-prototype-cnc-mills