Laser beam expanders increase the diameter of a collimated input beam to a larger collimated output beam for applications such as laser scanning, interferometry, and remote sensing. This work investigates how misalignments of collimation lenses afect two perfor-mance criteria: minimum throughput within an angular window and maximum beam height. Based on these criteria, we establish an alignment concept for the first section of a LiDAR emitter. Much of the specifics are left to the user as any system can. Laser diodes usually emit strongly diverging light, essentially because the emitting areas are normally quite small. Thin lens equation modified to be applicable for laser beams is introduced. In such systems, the object rays.