Image tracking of optical media using two wavelength optical head

A method for optically tracking recording media, comprising:

• providing a read/write laser having a first wavelength;
• providing an image tracking laser having a second wavelength different from the first wavelength;
• providing an objective lens having a first focal length for the first wavelength light and a second focal length for the second wavelength light, the first and second focal lengths being substantially different;
• directing light from the read/write laser through the objective lens so that the light is focused on a recording medium surface;
• and
• directing light from the image tracking laser through the objective lens toward the recording medium surface, wherein the light from the image tracking laser has an apparent focus at a point other than at the medium surface, whereby the image tracking laser provides optical tracking information.