We report the analysis, design and application of a Talbot interferometer in which the zero and first order beam from a grating are recombined. This interferometer produces fringes of the same period, d, as the master grating or phase mask rather than d/2 when the +/- 1 orders are employed. Experiments using the 0/1 Talbot interferometer with 193 nm ArF laser illumination to write gratings on polymers by ablation and photosensitive Bragg gratings in fibres are reported.