VCSEL laser, preparation method and laser radar

The invention belongs to the technical field of semiconductors, and particularly relates to a VCSEL (Vertical Cavity Surface Emitting Laser), which comprises at least one light-emitting unit, each light-emitting unit comprises a substrate layer, a first electrode, a first Bragg reflector, an active region, a current limiting layer, a second Bragg reflector, a second electrode and a current diffusion layer, the second electrode is located on the side, away from the substrate layer, of the current diffusion layer, the second electrode forms a closed ring on the current diffusion layer, and the second electrode extends to form a current diffusion electrode passing through the limiting hole; wherein a distance for laser to pass through is formed between the side wall of the current diffusion electrode and the inner wall of the second electrode, and current of the current diffusion electrode and the current diffusion layer passes through the second Bragg reflector and enters the active region from the middle regio