Method for manufacturing GRIN lens
US7921672B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 2005 |
| Grant date | Apr 12, 2011 |
| Priority date | — |
| Expiry date | Aug 17, 2027 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B2203/26
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method for manufacturing a GRIN lens includes the steps of forming a wet gel provided with a concentration distribution having a different concentration of a refractive index distribution imparting metal that differs in concentration in a radial direction, drying the wet gel to form a dry gel having a bulk specific gravity ρ (g/cm3), sintering the dry gel to form a GRIN lens base material and stretching the GRIN lens base material while heating. The method is characterized in that, in the step of sintering the dry gel, partial pressures of oxygen during sintering at 800° C. or higher are 10−1 Pa or lower and also the relation between a rate of temperature increase v (° C./hr) and a bulk density ρ of the dry gel during sintering at 1,000 to 1,150° C. is defined by v≦105*EXP (−12ρ). As a result of this, the GRIN lens, which has a large numerical aperture and a small diameter, can stably and easily be manufactured.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.