  A single-shot characterization of the temporal contrast of a petawatt laser
pulse with a high dynamic-range, is important not only for improving conditions
of the petawatt laser facility itself, but also for various high-intensity
laser physics experiments, which is still a difficult problem. In this study, a
new idea for improving the dynamic-range of a single-shot temporal contrast
measurement using novel temporal contrast reduction techniques is proposed. The
proof-of-principle experiments applying single stage of pulse stretching,
anti-saturated absorption, or optical Kerr effect successfully reduce the
temporal contrast by approximately one order of magnitude. Combining with the
SRSI-ETE method, its dynamic-range characterization capability is improved by
approximately one order of magnitude to approximately 109. It is expected that
a higher dynamic-range temporal contrast can be characterized using cascaded
temporal contrast reduction processes.
