Patent ID: 7978585

Claim:
An aberration correcting device configured to simultaneously correct a coma and an astigmatism of a laser light emitted from a semiconductor laser, the aberration correcting device comprising: a liquid crystal layer configured to vary in a refractive index in accordance with an electric field applied thereto; and a pair of transparent electrodes disposed to sandwich the liquid crystal layer, wherein, at least one of the pair of transparent electrodes includes a first circular dividing line substantially centrally disposed and a second circular dividing line disposed outside the first circular dividing line and substantially concentrically arranged therewith, wherein a region between the first circular dividing line and the second circular dividing line is radially divided by eight dividing lines at substantially regular intervals, and wherein a diameter of the first circular dividing line ranges from 0.2 to 0.35 while a diameter of the second circular dividing line ranges from 0.85 to 1 when assuming an effective-range diameter of the laser light as 1.