Outline of Technique
This section of the website outlines the techniques used for generation and detection of THz radiation; focussing on time domain spectroscopy. A computer simulation of the experiment is used in order to clarify the accompanying text.
The experimental prodcedure for THz time domain spectroscopy is outlined as follows:
- Generation of sub 100fs laser pulse and subsequent splitting of beam to form a probe pulse and (if required) an exitation pulse.
- Generation of THz pulse by ultra-fast charge transport or optical rectification. [See generation]
- Focussing of the free-space THz pulse onto sample using non-dispersive and abberation-free reflective optics.
- Detection of the transmitted THz pulse, through electro-optic sampling, or polarisation-sensitive photocurrent sampling. [See electro-optic sampling]
Videos of working THz systems are available, which show the timing and sequence of pulse generation, sample excitation, and pulse detection in a range of experiments:
Overview of Experimental Setup
The following is a computer generated image of the THz-TDS setup:
This particular setup uses electro-optic sampling as the detection technique and a photoconductive switch for generation of the THz pulse. For more information on these procedures please click on the relevant links on the menu above.
Photograph
Photograph of one of the THz time domain spectrometer systems at the Oxford Physics Terahertz Photonics group.
© 2007-2009 G. Jotzu, M. Cooper, P. Parkinson and M.B. Johnston
You are free to use this animation in a talk or on another website, however please acknowledge the authors and provide a link to http://www-thz.physics.ox.ac.uk.
If you have any queries please contact Michael Johnston, m.johnston@physics.ox.ac.uk
