Abstract: Systems and methods are described for reducing optical fiber splice loss. A torch is described for performing a thermally-diffused expanded core (TEC) technique. The torch includes a hollow body. A conduit delivers a flammable gas to the hollow body. The flammable gas streams out of an array of orifices formed in the hollow body. The orifices are shaped and arranged in the array such that when the streaming gas is ignited, a substantially continuous elongated flame is created having a desired heating profile. Further described are a thermal treatment station incorporating a line torch and techniques for using an elongated flame to reduce optical fiber splice loss.