Crystal-dithering method applied to spectral phase interferometry for direct electric-field reconstruction (SPIDER) for sensitivity enhancement of the pulse phase measurement

The application of a crystal-dithering technique to the spectral phase interferometry for direct electric-field reconstruction (SPIDER) was experimentally demonstrated. Applying a crystal-dithering technique to SPIDER resulted in the improvement of the measurement sensitivity. In our approach, a 20 μm-thick nonlinear crystal for a thin-crystal SPIDER method was replaced by a 100 μm-thick crystal, and the crystal was dithered. The improvement was confirmed by comparing the statistical error of the crystal-dithering SPIDER to the statistical error of the thin-crystal SPIDER method. The dispersion of a BK7 plate was investigated to evaluate the reliability of the proposed approach.