Title :
Transient conductivity in wide band-gap solids probed by THz pump-probe measurements
Author :
Shan, J. ; Wang, F. ; Knoesel, E. ; Bonn, M. ; Wolf, M. ; Heinz, T.F.
Author_Institution :
Dept. of Phys. & Electr. Eng., Columbia Univ., New York, NY, USA
Abstract :
Summary form only given. We have investigated sapphire (band-gap E/sub g/ = 8.7 eV) as a prototype crystalline insulator. The laser source for these measurements was an amplified, mode-locked Ti:sapphire system, which provided pulses of 100-fs duration and centered at a wavelength of 810 nm. Charge carriers in sapphire were created through a two-photon absorption process by femtosecond ultraviolet pulses (third harmonic). The pump-induced changes of the material were probed by THz electromagnetic pulses subsequent to the generation of the charge carriers. The THz pulse was generated and detected, respectively, by optical rectification and electro-optic sampling of the Ti:sapphire laser pulses in ZnTe crystals.
Keywords :
carrier density; carrier mobility; high-speed optical techniques; photoconductivity; sapphire; submillimetre wave spectra; two-photon processes; 100 fs; 8.7 eV; 810 nm; Al/sub 2/O/sub 3/; THz electromagnetic pulses; THz pulse detection; THz pulse generation; THz pump-probe measurements; Ti:sapphire laser pulses; ZnTe; ZnTe crystals; amplified mode-locked Ti:sapphire system; charge carrier creation; electro-optic sampling; femtosecond ultraviolet pulses; mobile carrier density; optical rectification; photogenerated charge carrier dynamics; prototype crystalline insulator; pump-induced changes; sapphire; time-resolved measurements; transient conductivity; two-photon absorption process; wide band-gap solids; Charge carrier density; Charge carrier mobility; Photoconductivity; Sapphire; Submillimeter wave spectroscopy; Ultrafast optics;
Conference_Titel :
Quantum Electronics and Laser Science Conference, 2002. QELS '02. Technical Digest. Summaries of Papers Presented at the
Conference_Location :
Long Beach, CA, USA
Print_ISBN :
1-55752-708-3
DOI :
10.1109/QELS.2002.1031289
