Accelerated method for increasing the photosensitivity of a glassy material

A method for producing an optical fiber having an optical grating, comprising the steps of:

• providing an optical fiber having a glass core and a thermally-stable exterior coating;
• exposing first and second portions of said optical fiber to a hydrogen-containing atmosphere under exposure conditions comprising (a) an exposure temperature of greater than 250° C., and (b) an exposure time of less than about 1 hour, thereby forming a treated optical fiber wherein the coating is thermally stable during and after the exposing step;
• and
• writing an optical grating on the treated optical fiber without removing the coating such that said first portion of the optical fiber contains the grating and said second portion of the optical fiber is devoid of any grating.

A method for improving the photosensitivity of an optical fiber, comprising the steps of:

• providing an optical fiber comprising a glass core and an exterior coating;
• and
• exposing the optical fiber to a hydrogen-containing atmosphere under exposure conditions comprising (a) a temperature of greater than 250° C., and (b) an exposure time of less than about 1 hour;
• wherein the coating is thermally-stable under the exposure conditions.

A method for producing an optical fiber having increased photosensitivity, comprising the steps of:

• providing an optical fiber comprising a glass core and a thermally-stable exterior coating;
• exposing the optical fiber to hydrogen gas heated to a temperature of greater than 250° C. until the optical fiber is essentially saturated with hydrogen, thereby forming a treated optical fiber and wherein the coating is thermally stable under the conditions at which it is exposed to the hydrogen gas;
• and
• rapidly cooling the treated optical fiber.

A method for increasing the photosensitivity of an optical fiber to actinic radiation, comprising the steps of:

• providing an optical fiber comprising a glass core and a thermally-stable exterior coating;
• and
• exposing the optical fiber to a hydrogen-containing atmosphere under exposure conditions comprising an exposure temperature of greater than 250° C., thereby forming a treated optical fiber;
• wherein the coating is thermally stable both during and after the exposing step such that the coating undergoes a weight loss of less than 10% by weight, based on the original weight of the coating material, when placed in a nitrogen atmosphere under the exposure conditions.