To easily correct wave aberration by providing the device with a light source, a transmitting part to transmit the light from the light source, a condensing part to condense the transmitted light by the transmitting part and to focus the light on a storage medium, and further with a controlling mechanism of divergence and convergence degrees to adjust the transmitting part to control the divergence and convergence degrees of the light transmitted by the transmitting part.
The collimated beam generated by a collimator 20 is passed through a reflection prism and refracted by a convergence lens 51 and a solid immersion lens(SIL) 52 to condense on a storage medium 70. In this process, wave aberration exists which is caused by errors in the distance between the convergence lens 51 and the SIL 52, errors in the position of the lenses in the perpendicular direction to the optical axis, or errors in the thickness of the SIL 52. The wave aberration can be suppressed by moving a first converting lens 22 in the parallel direction to the optical axis by an actuator 30 so as to adjust the collimation degree of the collimated beam generated by the collimator 20 and to convert the collimated beam into a little convergent beam or divergent beam.
YOSHIKAWA HIROYASU
HASEGAWA SHINYA
