Optical system with aberration suppression and optical head utilizing the same
US5161040A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 29, 1990 |
| Grant date | Nov 3, 1992 |
| Priority date | — |
| Expiry date | Jan 29, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0908
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical system, that includes a light source having sufficient coherency to provide a predominate operating wavelength and a diffraction grating lens system to focus the light from the light source to an image point on the optical axis of the optical system, provides for change of position of the image point along the optical axis over a wide focusing range with suppression of generated aberration. In particular, the optical system comprises a light source both movable in the direction of the optical axis and capable of variation in wavelength and a diffraction grating lens system that condenses the beam from the light source onto an image point on and along the optical axis, which system is effective in cancelling out aberration generated due to movement of the light source. The spherical aberration associated with the movement of the image spot brought about by the movement of the light source or its equivalent in the optical system is cancelled out by the chromatic aberration generated by the diffraction grating created by adjustment the light source wavelength.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.