System and method for nitrogen doping of a glass article

A method of doping a glass article with nitrogen, comprising:

• supplying a nitridizing gas to a glass article through an outlet of a gas supply conduit, wherein the nitridizing gas comprises gaseous NH3, and wherein a distance between the outlet and the glass article is less than or equal to about 10 cm;
• heating the glass article in a furnace to a first temperature in the presence of the nitridizing gas to form a nitrogen-doped glass article, and
• wherein a residence time of the nitridizing gas is <3.0 seconds, and wherein the residence time is defined by formula (III):
• Vt/f (III)
• where Vt is an interior volume of the gas supply conduit between a position at which a temperature of the nitridizing gas is >500° C. and the outlet, and where f is the volumetric flow rate of the nitridizing gas in the gas supply conduit.

A method of doping a glass preform with nitrogen, comprising:

• disposing a glass preform having a first end and a second end in a furnace assembly, wherein the glass preform includes an open channel extending from the first end at least partially through a body of the glass preform toward the second end;
• supplying a nitridizing gas to the open channel of the glass preform through a gas supply pathway having an outlet aligned with an inlet to the open channel, wherein the nitridizing gas comprises gaseous NH3;
• heating the glass preform to a first temperature in the presence of the nitridizing gas to form a nitrogen-doped glass preform;
• and
• wherein a residence time of the nitridizing gas is <3.0 seconds, and wherein the residence time is defined by formula (III):
• Vt/f (III)
• where Vt is an interior volume of the gas supply pathway between a position at which a temperature of the nitridizing gas is >500° C. and an end of the open channel, and where f is the volumetric flow rate of the nitridizing gas in the gas supply pathway.