| 摘要 |
The invention relates to an apparatus and a method for investigating a sample by means of THz radiation. The same optical non-linear member is used as an active part of the emitter and as an active part of the detector. The optical non-linear member is irradiated with a pulsed optical beam under conditions that allow THz generation. The THz beam is split off the optical beam, directed onto the sample, and reflected back onto the non-linear member. The optical beam is also, after recombination with the THz beam, reflected back onto the non-linear member. According to the invention, optical properties of the reflected optical beam, which are influenced by the co-propagating THz beam, are measured and evaluated. The reflected optical beam thus acts as probe beam. The invention has the advantage that more intensity is available for each of the processes THz generation and THz detection, as pump beam and probe beam are generally the same. |
