is a

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

ese global

glass manufacturing Glass production involves two main methods – the float glass process that produces sheet glass, and glassblowing that produces bottles and other containers. It has been done in a variety of ways during the history of glass. Glass container ...

company. The company is headquartered in Sagamihara with subsidiaries in a number of countries, including Japan, the United States, Germany, Hong Kong, Malaysia, Taiwan, and China, with Ohara Corporation being the U.S. subsidiary of the Ohara Group. Ohara manufactures glasses since 1935, the year of its founding. Their web site lists areas of specialization, including: * Optical Glass * Polished Substates * Fused Silica and Quartz * IR Materials and Optical Crystals * Low Expansion Glass * Glass Ceramics * Measurement Services

Optical glass

Among other things, Ohara is a major supplier of optical glass. Lens design programs will typically include glasses in the Ohara catalog among their stock material choices, along with, for example, glasses in the Schott catalog. On their website, Ohara describes a line of more than 130 environmentally safe glasses, produced without lead and arsenic. They produce more than 300 tons of optical glass a month (against 10800 tons/month for Schott and over 108000 tons/month for Corning). The glass is available in a variety of forms, including strip, slab, cut blanks, and pressings. Ohara includes in its catalog the famous E6 borosilicate (similar to Corning's Pyrex), ClearCeram-Z (a vitroceramic similar to Schott's Zerodur), and two well-known low dispersion glasses: FPL51 (the UD glass used by Canon) and FPL53 showing properties close to fluorite.

Telescope mirror glass

Ohara supplied over 23.5 tons of their E6

borosilicate glass Borosilicate glass is a type of glass with silica and boron trioxide as the main glass-forming constituents. Borosilicate glasses are known for having very low coefficients of thermal expansion (≈3 × 10−6 K−1 at 20 °C), ma ...

, the purest optical glass in the world, to be cast into the blank of the primary and tertiary mirror of the

Large Synoptic Survey Telescope The Vera C. Rubin Observatory, previously referred to as the Large Synoptic Survey Telescope (LSST), is an astronomical observatory currently under construction in Chile. Its main task will be carrying out a synoptic astronomical survey, the Le ...

. E6 glass was also used to manufacture the mirror of the

Giant Magellan Telescope The Giant Magellan Telescope (GMT) is a ground-based extremely large telescope under construction, as part of the US Extremely Large Telescope Program (US-ELTP), . It will consist of seven 8.4 m (27.6 ft) diameter primary segments, that ...

and the

Large Binocular Telescope The Large Binocular Telescope (LBT) is an optical telescope for astronomy located on Mount Graham, in the Pinaleno Mountains of southeastern Arizona, United States. It is a part of the Mount Graham International Observatory. When using both 8 ...

, both having a primary mirror 8.4 m wide.

References

External links

Ohara Group
{{Glass makers and brands Glassmaking companies of Japan Defense companies of Japan Companies listed on the Tokyo Stock Exchange Companies based in Kanagawa Prefecture Manufacturing companies established in 1935 Glass trademarks and brands Multinational companies headquartered in Japan Japanese brands Japanese companies established in 1935