The invention relates to the technical field of an optical lens, in particular to a high-resolution, large-image-plane, small-size and
infrared confocal zoom optical
system, which is sequentially provided with, from an object side to an image side, a first lens group with a positive
focal length, a second lens group with a negative
focal length, a diaphragm, a third lens group with a positive
focal length, a fourth lens group with a positive focal length and a photosensitive
chip. The first lens group, the diaphragm and the third lens group are fixed with respect to the photosensitive
chip, the second lens group and the fourth lens group can move forward and backward with respect to the photosensitive
chip, the second lens group moves toward the third lens group gradually when the opticalsystem changes from a short focal length to a long focal length, and a focusing effect is realized when the fourth lens group moves with respect to the photosensitive chip. The third lens group includes three lenses, wherein one
aspheric lens in the third lens group and one
aspheric lens arranged in the second lens group can perform aberration correction. An
aspheric lens in the fourth lens groupcan perform correction of the field curvature.