Analysis of chromatic aberration of single objective lens and correction of that of a NA=0.85 objective lens

摘要

Blu-ray system that has 23.3 Gbyte capacities has been developed. For the objective lens, we have reported a single objective lens with a numerical aperture (NA) of 0.85. A single lens is the simplest lens, but they unfortunately have a limited number of design freedoms. Therefore, well-considered lens design is very important to realize a high quality lens. For this reason, we have analyzed a general principle of the aplanatic single lens design. Another important issue of the single lens design is chromatic aberration because high NA and shorter wavelength produce significant increase of it. In this report, we will analyze the chromatic aberration of single lenses by extending the equations in the previous report. The design of a chromatic corrector and experimental results will also be discussed.