In-fiber Bragg reflectors produced with coherent, transverse uv illumination promise to be versatile optical elements for spectral selection and distributed sensing. These fiber devices were generated by repetitive exposures to a moderate intensity, frequency-doubled dye laser under holographically stable conditions until sufficient periodic index modulation had accumulated to produce a strong reflection. Fluences in the range of 1000 J/cm2 were delivered over the course of many seconds to minutes to obtain an index modulation depth of approximately 1 X 10-4. In an alternate approach, we used single approximately 1 J/cm2 pulses from a line-narrowed KrF excimer to produce gratings with a modulation depth of approximately 2 X 10-5, and more recently have achieved values > 1 X 10-4. An unanticipated benefit of the single-pulse preparation method appears to be the markedly enhanced thermal stability of the grating structure as compared to that reported for gratings produced with multiple exposures.