Gigahertz time-domain spectroscopy and imaging for non-destructive materials research and evaluation.
By using optical sampling with repetition frequency modulation of pump/probe laser pulses on photoconductive emitter/detector antennas, the high-speed time/frequency domain gigahertz imaging is reported due to the absence of opto-mechanical delay line in this optical scheme. The clear contrast for a 3-cm wide metal plate, which was placed behind a 5-cm thick concrete block, was observed with a 1 × 1 mm image pixilation. On average, it took only ~0.75 s per pixel/waveform acquisition/assignment with a 675 ps time-domain window. This could become a valuable non-destructive evaluation technique in gigahertz spectral range with all benefits of time-domain spectroscopy.
National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.|Research Center for Development of Far-Infrared Region, University of Fukui, Fukui, 3-9-1 Bunkyo, 910-8507 Japan.
Dmitry S
DS
Bulgarevich
National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
Mitsuharu
M
Shiwa
Research Center for Development of Far-Infrared Region, University of Fukui, Fukui, 3-9-1 Bunkyo, 910-8507 Japan.
Takashi
T
Furuya
Research Center for Development of Far-Infrared Region, University of Fukui, Fukui, 3-9-1 Bunkyo, 910-8507 Japan.
Masahiko
M
Tani