An apparatus for producing a glass soot includes a first a burner having a droplet-emitting first region, a gas-emitting second region surrounding the first region, and a gas-emitting third region surrounding the second region. The first region emits a glass-forming mixture, the second region emits an inert gas, and the third region emits a combination of oxygen and a combustible gas. The apparatus further includes a combustion area having a first section proximate the first burner and a second section distal from the first burner. A glass-forming mixture is at least partially vaporized in the first section of the combustion area. The apparatus further includes at least one secondary burner having gas-emitting fourth and fifth regions. The fourth region of the secondary burner emits oxygen and the fifth region of the secondary burner emits a combustible gas. The second section of the conversion area is in communication with the fourth and fifth regions of the secondary burner, such that the glass-forming mixture is completely vaporized and converted into a glass soot deposited on a preform such as a bait rod. The invention also includes a method of enhanced vaporization using first and second spaced apart combustion areas.