The compatible type optical pickup device is capable of recording and reproducing optical disks in different disk substrate thickness such as BD and HD DVD or the like. In more detail, an optical pickup can record and reproduce the media of two or more kinds in different substrate thickness using almost identical wavelength or the identical laser source. One is provided as the infinite type optical system and the other is provided as the finite type optical system using an expander lens. Accordingly, the optical disks of different substrate thickness such as BD and HD DVD can be recorded and reproduced with compatibility using the identical wavelength of light.