High-power single-cycle THz emission from large-area photoconductive emitters at 400 kHz

This dataset accompanies the paper "High-power single-cycle THz emission from large-area photoconductive emitters at 400 kHz"

General data acquisition:

THz is generated with the Microstructured large-area photoconductive terahertz emitters at room temperature. The excitation pump power is controlled by a motorized lambda/2-waveplate  in connection with a thin-film polarizer. The bias voltage is generated with a waveform generator (keysight 33500B) in combination with a voltage amplifier (Falco WMA-300). The probe beam for electro-optic sampling (EOS) is guided over an oscillating delay line, having a delay range of approximately 15 ps and a shaking frequency of 10 Hz, leading to 1565 THz traces in over 78 s measurement time.

THz traces were obtained with EOS and a lock-in amplifier for low noise detection. The average power is measured with a pyroelectric power meter (Ophir, 3A-P-THz). The data for Fig.2 are provided in the Excel file "PumpSpotSweep_400kHz_25V". Each sheet name corresponds to the pump spot diameter on the LAE. In each sheet, the column named "pump power (W)" corresponds to optical pump power, and measured THz power after correction is in a column named  "THz corrected". the correction factors consist THz transmission through low pass filters and calibration factor for the THz power meter. In a similar way, data in Fig.3 are provided in an Excel file with the name "Fluence_Vs_BiasVotage". Each sheet name corresponds to the applied bias voltage (peak-to-peak) on the LAE. In each sheet, the column named "pump power (W)" corresponds to optical pump power, and measured THz power after correction is in a column named  "THzCorrected". the correction factor is calculated at explained earlier.

The recorded data via lock-in amplifier are saved in HDF-5 format. The EOS trace in the file name is "150kHz_000", and the dark trace "dark1_150kHz_000". For convenient, the THz and noise trace in the time domain were also extracted in at CSV file.

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 “HDFView” can be downloaded for free (after registration) from https://www.hdfgroup.org/downloads/hdfview/. It allows to explore the folder structure of an HDF-5 file but is not necessary when using Python or Matlab.

The structure of a single HDF-5 from the uploaded raw data is

A folder called "AI", standing for analog input

The dataset "AI 1" stands for the first analog channel, containing the position of the scanning delay line. The voltage can be converted to “THz time” with a conversion factor, where 20 V corresponds to a 15 ps delay.

The dataset “AI 2”, is a voltage signal from the transimpedance amplifier and is proportional to the THz electric field.

There are additional attributes in the root-folder of the HDF-5 file.