|Budget Amount *help
¥49,010,000 (Direct Cost: ¥37,700,000、Indirect Cost: ¥11,310,000)
Fiscal Year 2014: ¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000)
Fiscal Year 2013: ¥8,320,000 (Direct Cost: ¥6,400,000、Indirect Cost: ¥1,920,000)
Fiscal Year 2012: ¥16,250,000 (Direct Cost: ¥12,500,000、Indirect Cost: ¥3,750,000)
Fiscal Year 2011: ¥17,940,000 (Direct Cost: ¥13,800,000、Indirect Cost: ¥4,140,000)
|Outline of Final Research Achievements
We have developed broadband single-shot femtosecond spectroscopy in time-frequency space using a reflective echelon mirror. The echelon mirror is employed to make a spatially encoded time-delay for the white-light continuum probe pulse; it produces a temporal step of 66 fs and an overall time-delay of 33 ps. By utilizing this technique, we have observed not only an internal conversion dynamics in organic molecules but also an ultrafast crystalline-to-amorphous phase-change in chalcogenide alloys.
In case of chalcogenide alloys, the observed rise time to reach the amorphization was 130~200 fs, suggesting that the ultrafast amorphization can be attributed to the rearrangement of Ge atoms from an octahedral to a tetrahedral structure.
We also revealed the excited states and photo-sensitization effects in several UV absorbers, which are next targets to perform our single-shot spectroscopy.