A method for manufacturing an optical device includes a hydrogen-loading step, a laser irradiation step, and a light condensing point movement step. A continuous refractive index changed region is formed in a glass member by alternately repeating the laser irradiation step and the light condensing point movement step or performing the laser irradiation step and the light condensing point movement step in parallel. In the hydrogen-loading step, hydrogen is loaded into the glass member containing P.sub.2O.sub.5 as a main component. In the laser irradiation step, a femtosecond laser beam having a repetition frequency of 10 kHz or higher is condensed in the hydrogen-loaded glass member, and a light-induced change in refractive index is caused in the glass member. In the light condensing point movement step, a light condensing point position of the femtosecond laser beam is moved relative to the glass member.

A method for manufacturing an optical device includes a hydrogen-loading step, a laser irradiation step, and a light condensing point movement step. The laser irradiation step and the light condensing point movement step are alternately repeated, or are performed in parallel. In the hydrogen-loading step, hydrogen is loaded into a glass member containing B.sub.2O.sub.3 and has a content of GeO.sub.2 less than 10% by mass fraction based on an oxide. In the laser irradiation step, a femtosecond laser beam having a repetition frequency of 10 kHz or higher is condensed and emitted into the glass member into which the hydrogen is loaded, and a light-induced change in refractive index is caused in the glass member. In the light condensing point movement step, a light condensing point position of the femtosecond laser beam is moved relative to the glass member.

A synthetic quartz glass substrate having a controlled hydrogen molecule concentration is prepared by (a) hot shaping a synthetic quartz glass ingot into a glass block, (b) slicing the glass block into a glass plate, (c) annealing the glass plate at 500-1,250 C. for 15-60 hours, (d) hydrogen doping treatment of the glass plate in a hydrogen gas atmosphere at 300-450 C. for 20-40 hours, and (e) dehydrogenation treatment of the glass plate at 200-400 C. for 5-10 hours.

Chemically-strengthened thin glass having modified curvature and a method for making the same. The method includes providing a thin glass substrate which has host alkali ions situated in its surface regions, and possesses a treatment-advantaged surface region and a treatment-disadvantaged surface region located opposing each other; conducting a step of ion-exchange with invasive alkali ions having an average ionic radius larger than the average ionic radius of the host alkali ions, thereby producing a chemically-strengthened substrate which is characterized by an undesired curvature (warpage), and then conducting a step of reverse ion-exchange with reversing alkali ions having an average ionic radius equal to, or smaller than, the average ionic radius of the host alkali ions before ion-exchange, so as to produce a chemically-strengthened substrate having either less curvature or having a predetermined profile of curvature, which is not present in the chemically-strengthened glass substrate prior to reverse ion-exchange.

An article comprises a body having a coating. The coating comprising a eutectic system having a super-lattice of a first fluoride and a second fluoride. The coating includes a glaze on a surface of the coating, the glaze comprising the eutectic system having the super-lattice of the first fluoride and the second fluoride.

A transparent timepiece component, in particular a watch glass, has a substantially planar or curved interior surface, and has mainly a transparent material colored by a zone of modified chemical composition within the component through an introduction of at least one coloring chemical element of the transparent material, this zone of modified chemical composition extending in one part only of the total thickness of the timepiece component.

Glass-based articles that include a compresive stress layer extending from a surface of the glass-based article to a depth of compression are formed by exposing glass-based substrates to water vapor containing environments. The glas-based substrates are substantially free or free of alkali metal oxides. The methods of forming the glass-based articles may include elevated pressures and/or multiple exposures to water vapor containing environments.

Glass-based articles that include a compressive stress layer extending from a surface of the glass-based article to a depth of compression are formed by exposing glass-based substrates to water vapor containing environments. The methods of forming the glass-based articles may include elevated pressures and/or multiple exposures to water vapor containing environments.

Laminated glass articles and glass-based articles are disclosed. According to one embodiment, a laminated glass article includes a glass core layer comprising an average core coefficient of thermal expansion CTE.sub.C and at least one glass clad layer fused directly to the glass core layer, the at least one glass clad layer comprising an average clad coefficient of thermal expansion CTE.sub.CL. CTE.sub.C is greater than or equal to CTE.sub.CL. The glass core layer, the glass clad layer, or both, include a hydrogen-containing core zone.

There is provided a method of processing an oxygen-containing workpiece. The method of processing an oxygen-containing workpiece includes controlling a fluorine concentration in the oxygen-containing workpiece based on at least one of a kind of a fluorine-containing processing gas, a processing temperature and a processing pressure used for processing the oxygen-containing workpiece.