Photoconductive receivers at 1030 nm for high average power pulsed THz detection

<p>This dataset is accompanying the paper &quot;Photoconductive receivers at 1030 nm for high average power pulsed THz detection&quot;</p> <p><strong>General data acquisition:</strong></p> <p>THz is generated with the tilted pulse front approach in lithium niobate at room temperature. The pump power is controlled by a motorized lambda/2-waveplate (PI DT-80) in connection with a thin-film polarizer and calibrated to a THz power meter (Ophir 3A-P-THz). The computer-controlled rotation stage allows to sweep the THz power in a reliable and reproduceable way. The probe beam is guided over an oscillating delay line, having a delay range of approximately 15 ps and a shaking frequency of 20 Hz, leading to 4800 THz traces in over 2 min measurement time. In the path of the probe beam is also a motorized rotation stage and a polarizer positioned, to control the laser probe power in the same way as the THz pump power.</p> <p>The THz is received by a ErAs:InAlGaAs photoconductive antenna (PCA) developed at TU Darmstadt, which is optimized for 1030 nm. The THz receiving side has a silicon lens, concentrating the THz radiation on an H-dipole antenna with a center dipole length of 25 &micro;m and a photoconductive gap of 5 &micro;m. On the backside, the probe beam is coupled with a microscope objective for the near infrared range (Mitutoyo M Plan Apo NIR 20X). The small current of the PCA receiver is converted to a useable voltage range with a transimpedance amplifier (Femto DLPCA-200) with a gain of 10^7 V/A.</p> <p>For each combination of THz pump power and laser probe power (sampling beam), a measurement file with 2 min recording length and a sampling rate of 200 kSa/s is recorded with the DAQ (Dewesoft Sirius Mini). The exported file-format HDF-5.</p> <p>HDF-5 is an efficient (binary), cross-platform data format and can be read easily by i.e. Python or Matlab. The graphical user interface &ldquo;HDFView&rdquo; can be downloaded for free (after registration) from <a href="https://www.hdfgroup.org/downloads/hdfview/">https://www.hdfgroup.org/downloads/hdfview/</a>. It allows to explore the folder structure of an HDF-5 file but is not necessary when using Python or Matlab.</p> <p>The structure of a single HDF-5 from the uploaded raw data is</p> <ul> <li>A folder called &quot;AI&quot;, standing for analog input <ul> <li>The dataset &quot;AI 1&quot; stands for the first analog channel, containing the position of the scanning delay line. The voltage can be converted to &ldquo;THz time&rdquo; with a conversion factor, where 20 V correspond to 15 ps delay.</li> <li>The dataset &ldquo;AI 2&rdquo;, which is voltage signal from the transimpedance amplifier and proportional to the THz electric field.</li> </ul> </li> </ul> <p>There are additional attributes in the root-folder of the HDF-5 file.</p> <p>The processed data (used in the figures) can be found in the files labeled Fig.X.h5, except for Fig.7, which only contains a single curve and is a .txt file.</p>