FDTD software

 

Simulation of time-resolved THz spectroscopy experiments

In a recent paper in Journal of the Optical Society of America B we have reported on the numerical analysis of a time-resolved terahertz (THz) spectroscopy experiment using a modified finite-difference time-domain method. Using this method, we show that ultrafast carrier dynamics can be extracted with a time resolution smaller than the duration of the THz probe pulse and can be determined solely by the pump pulse duration. Our method is found to reproduce complicated two-dimensional transient conductivity maps exceedingly well, demonstrating the power of the time-domain numerical method for extracting ultrafast and dynamic transport parameters from time-resolved THz spectroscopy experiments.

The basis of the work in that paper is a Matlab-based simulation tool written by Casper Larsen, who was the Master student carrying out the vast majority of the work in the project. We have decided to make the code freely available. If you fill out the form below (name, email, and organization type) you will get access to a file containing the necessary code, a short user manual, and short tutorials with instructive examples to illustrate the use of the code.

Figure 1: Illustration of the numerical setup for FDTD modelling of TRTS experiments. A source injects the THz probe pulse, a pump excites carriers in the sample, and detectors measure reflection and transmission: PML, perfectly matched layer boundary conditions.

Figure 2: Real (s1) and imaginary (s2) part of the induced photoconductivity in GaAs following excitation with 45 fs, 800 nm, 7 mJ/cm2 laser pulses. Left panel shows experimental results, right panel shows FDTD simulation results, including detector response and aperture functions.

Figure 2 shows an example of the agreement between experiment (left) and simulation (right) which is possible with the simulation tool that you can download below.

Do you want to be able to model your time-resolved THz spectroscopy experiments with high precision? Then use the link (right click/save as… works best) below to download the package for Matlab! The package includes educational tutorials, and contains all required scripts.

Download CLFDT_0.3.zip

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© 2012 Terahertz.dk Our research is carried out at DTU Fotonik - Department of Photonics Engineering, Technical University of Denmark. Suffusion theme by Sayontan Sinha