Transient changes in the complex conductivity of the high-temperature superconductor YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7</sub> have been measured with optical-pump THz-probe spectroscopy. Artifacts in the conductivity arise when optical excitation induces changes in the material response that occur on a time scale comparable with or faster than the THz pulse width. A model is presented that agrees with experiments and provides insight in distinguishing between artifacts and real features in transient conductivity measurements.
© 2000 Optical Society of America
(260.3090) Physical optics : Infrared, far
(300.6270) Spectroscopy : Spectroscopy, far infrared
(320.0320) Ultrafast optics : Ultrafast optics
(320.5390) Ultrafast optics : Picosecond phenomena
Richard D. Averitt, George Rodriguez, Jennifer L. W. Siders, Stuart A. Trugman, and Antoinette J. Taylor, "Conductivity artifacts in optical-pump THz-probe measurements of YBa2Cu3O7," J. Opt. Soc. Am. B 17, 327-331 (2000)