JVC has developed a prototype single-objective glass lens with what is said to be the world's highest numerical aperture (NA) of 0.95.

Combined with the blue-violet laser diode with a wavelength of 405nm, the lens can boost the capacity of a 12cm-diameter optical disc to more than 40GB on both sides, in theory, according to the company.

Victor also expects to improve production yields and to sharply cut the current lens size, if it applies this newly developed production technology to objective lenses for Blu-ray Discs (BD).

The company is to disclose details of this achievement at ISOM '04, an international symposium on optical disc-related technologies, held on Jeju Island, Korea.

It has been extremely difficult to secure the sharp slope of the lens face as precisely as required when molding a glass lens with such a high NA as 0.95. According to an employee, Victor has achieved a molding error of less than 0.1 micron, an equivalent error that occurs with its existing NA 0.85 lenses, by "polishing every molding technology, such as mold processing, mold measuring, press and lens designing technologies."

Victor Japan intends to adapt this technology to its NA 0.85 objective lenses for BD. The technology is expected to promote the use of BD devices in mobile equipment, such as portable BD players.