Fourier Transform Analysis of Terahertz Radiation

Advances in terahertz radiation (T-rays) technology have great promise in various technological areas ranging from medical technology, imaging technology and accelerator technology. At Thomas Jefferson Laboratory, the Free Electron Laser division (FEL) produces very powerful beam of laser light by accelerating electrons in bunches along a beamline. This laser light absorbs and releases energy at various wavelengths. The new FEL upgrade led to the production of very bright terahertz (THz) radiation with an average power of 1 00watts which is about 100,000 times brighter than those produced elsewhere. These T-rays have very significant applications in the Laboratory. The most significant application is in FEL electron beam diagnostics. Analysis and signal processing of Terahertz radiation is one method of performing electron beam diagnostics. This process basically measures something proportional to the electron bunch length. These measurements are significant to the FEL because of the setbacks caused by the dependence of the FEL laser gain on the electron beam peak current and the slippage effect. Several analytical techniques for processing terahertz radiation have been reported, however in this work T-rays are processed using Labview 7 .1. The results obtained would be used in acquiring bunch length measurements at the FEL.