US 2004/0055336 A1 · Optical apparatus

Abstract

An optical apparatus includes a container filled with a gas containing hydrogen, and an optical element of silica glass which is accommodated in the container. The optical element is subjected to a heat treatment in a hydrogen atmosphere before being accommodated in the container. Within the container, the hydrogen concentration of the gas containing hydrogen is set to be less than 4% by volume, and the hydrogen having a partial pressure of in the range of 0.01 to 500 kgf/cm2 (0.98 to 49,000 kPa). By maintaining the optical element in an ambient containing hydrogen, defects in the silica glass are minimized even when high energy light such as ultraviolet light is emitted over a long period. Therefore, an increase in transmission loss and optical distortions in the silica glass are prevented.

Claims26

Dependent claims

An optical apparatus comprising:

a container filled with a gas containing hydrogen;
an optical element of silica glass, accommodated in said container;
and
a light source emitting coherent light,
wherein the hydrogen has a partial pressure of 0.01 to 500 kgf/cm2, and
wherein said optical element and said light source are aligned so that the coherent light emitted from said light source is incident upon said optical element.

3 more elements

Dependencies are inferred from the claim text.

Optical apparatus

Life of this patent

Optical apparatus

Life of this patent

Abstract

Claims26