PICKUP LENS WITH PHASE COMPENSATOR AND OPTICAL PICKUP APPARATUS USING THE SAME

摘要

A pickup lens with a phase compensator is composed of a condenser lens and a phase compensator. At least one surface of the condenser lens has a step-like annular zone structure to compensate wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of t1 with a laser beam having a wavelength lambda1 and wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of t2 with a laser beam having a wavelength lambda2. The phase compensator compensates wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of t3 with a laser beam having a wavelength lambda3.