The two-line atomic fluorescence (TLAF) is a promising technique for temporally-and spatially-resolved temperature diagnostics, based on laser-induced fluorescence principles, in diffusion flames. In this thesis, a two-dimensional TLAF technique with indium seeding was designed and the building of the experimental set-up was completed. The two excitation wavelengths for indium were provided by two dye lasers pumped by two Nd:YAG lasers. The two line approach makes TLAF measurements independent of indium concentration variation and quenching. Indium chloride was used as the atomic indium source. Preliminary experiments were conducted on a diluted laminar diffusion flame. Preliminary results implied that minor system improvements increasing signal strength are, necessary to ensure sufficient signal-to-noise ratio for temperature measurements. Results also suggested that, pending on minor improvements, spatially and temporally resolved TLAF temperature measurements are feasible in certain diffusion flames.