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

fYear

2002

fDate

19-24 May 2002

Firstpage

187

Lastpage

188

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;

fLanguage

English

Publisher

ieee

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

Type

conf

DOI

10.1109/QELS.2002.1031289

Filename

1031289