Abstract

Blu-ray system that has approximately 25 Gbyte capacities has been developed¹⁾. GaN laser and an objective lens with a numerical aperture (NA) of 0.85 are key elements for this system. For the objective lens, we have reported a single objective lens²⁾. 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 design³⁾. The manufacturing tolerance was also discussed. 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.

© 2003 Optical Society of America