Abstract
Ein Terahertz-Time-Domain-Spektroskopie- (THz-TDS-) System mit elektrooptischem Detektor auf der Basis von ZnTe wird vorgestellt. Als Laserquelle dient ein Ti:Sa-Laser, der Laserpulse mit einer Dauer von ca. 10 fs bei einer zentralen Wellenlänge von 800 nm liefert. Durch Optimierung des Detektionsverfahrens wurde mit nur 25 mW Laserleistung ein Signal-Rausch-Verhältnis (SNR) von größer als 103 erzielt. Die aufgenommenen Spektren bekannter Substanzen weisen materialspezifische Absorptionslinien auf und erlauben deren eindeutige Erkennung.
Abstract
A Terahertz Time-Domain Spectroscopy (THz-TDS) system with electro-optical detector based on a ZnTe crystal is presented. The pump laser is a Ti:Sa laser with pulse duration of approx. 10 fs at a central wavelength of 800 nm. Using an optimized detection configuration, a signal-to-noise ratio better than 103 is achieved, applying an optical laser power of only 25 mW. Several substances can be clearly distinguished on the basis of their specific THz absorption spectra.
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