Synthetic silica glass, especially for the cladding of an optical fiber and a manufacturing method for the synthetic silica glass

An article of manufacture comprising synthetic silica glass, said synthetic silica glass having:

• paramagnetic E′ defect centers in an amount sufficient that the synthetic silica glass has an absorption coefficient at 215 nm in a range from 0.001 cm −1 to 2 cm−1 ;
• paramagnetic oxygen defect centers (ODC defect centers) in an amount sufficient that the synthetic silica glass has an absorption coefficient at 250 nm in a range from 0.001 cm −1 to 2 cm−1 ;
• an OH group concentration of 5 wtppm or less;
• a viscosity at 1100° C. in a range from 1×1013.5 poise to 1×1015.5 poise;
• and
• a total content of aluminum that is in a range from 1 wtppm to 10,000 wtppm;
• wherein said synthetic silica glass has, in a wavelength range between 600 nm and 1700 nm, a relative refractive index difference that is in a range from +0.03% to +3% relative to a synthetic fused silica glass having an absorption coefficient at 215 nm less than 0.001 cm−1, and an absorption coefficient at 250 nm of less than 0.001 cm−1;
• and
• wherein said article is a fiber laser device.

An article of manufacture comprising synthetic silica glass, said synthetic silica glass having:

• paramagnetic E′ defect centers in an amount sufficient that the synthetic silica glass has an absorption coefficient at 215 nm in a range from 0.001 cm −1 to 2 cm−1;
• paramagnetic oxygen defect centers (ODC defect centers) in an amount sufficient that the synthetic silica glass has an absorption coefficient at 250 nm in a range from 0.001 cm −1 to 2 cm−1;
• an OH group concentration of 5 wtppm or less;
• a viscosity at 1100° C. in a range from 1×1013.5 poise to 1×1015.5 poise;
• and
• a total content of aluminum that is in a range from 1 wtppm to 10,000 wtppm;
• wherein said synthetic silica glass has, in a wavelength range between 600 nm and 1700 nm, a relative refractive index difference that is in a range from +0.03% to +3% relative to a synthetic fused silica glass having an absorption coefficient at 215 nm less than 0.001 cm−1 , and an absorption coefficient at 250 nm of less than 0.001 cm −1 ,
• wherein said synthetic silica glass is a core glass, and wherein the article further comprises a cladding glass layer around said core glass, and wherein the core glass and the cladding glass layer are parts of a preform for a step-index optical fiber.