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dc.contributor.advisor Mittleman, Daniel M.
dc.creatorPearce, Jeremiah Glen
dc.date.accessioned 2009-06-04T08:43:20Z
dc.date.available 2009-06-04T08:43:20Z
dc.date.issued 2005
dc.identifier.urihttps://hdl.handle.net/1911/18797
dc.description.abstract Propagation of single-cycle terahertz (THz) pulses through a random medium leads to dramatic amplitude and phase variations of the electric field because of multiple scattering. We present the first set of experiments that investigate the propagation of THz pulses through scattering media. The scattering of short pulses is a relevant subject to many communities in science and engineering, because the properties of multiply scattered or diffuse waves provide insights into the characteristics of the random medium. For example, the depolarization of diffuse waves has been used to form images of objects embedded in inhomogeneous media. Most of the previous scattering experiments have used narrowband optical radiation where measurements are limited to time averaged intensities or autocorrelation quantities, which contain no phase information of the pulses. In the experiments presented here, a terahertz time-domain spectrometer (THz-TDS) is used. A THz-TDS propagates single-cycle sub-picosecond pulses with bandwidths of over 1 THz into free space. The THz-TDS is a unique tool to study such phenomena, because it provides access to both the intensity and phase of those pulses through direct measurement of the temporal electric field. Because of the broad bandwidth and linear phase of the pulses, it is possible to simultaneously study Rayleigh scattering and the short wavelength limit in a single measurement. We study the diffusion of broadband single-cycle THz pulses by propagating the pulses through a highly scattering medium. Using the THz-TDS, time-domain measurements provide information on the statistics of both the amplitude and phase of the diffusive waves. We develop a theoretical description, suitable for broadband radiation, which accurately describes the experimental results. We measure the time evolution of the degree of polarization, and directly correlate it with the single-scattering regime in the time domain. Measurements of the evolution of the temporal phase of the radiation demonstrate that the average spectral content depends on the state of polarization. In the case of broadband radiation, this effect distinguishes photons that have been scattered only a few times from those that are propagating diffusively.
dc.format.extent 118 p.
dc.format.mimetype application/pdf
dc.language.iso eng
dc.subjectElectronics
Electrical engineering
Physics
Electromagnetics
Optics
dc.title Multiple scattering of broadband terahertz pulses
dc.type.genre Thesis
dc.type.material Text
thesis.degree.department Physics
thesis.degree.discipline Natural Sciences
thesis.degree.grantor Rice University
thesis.degree.level Doctoral
thesis.degree.name Doctor of Philosophy
dc.identifier.citation Pearce, Jeremiah Glen. "Multiple scattering of broadband terahertz pulses." (2005) Diss., Rice University. https://hdl.handle.net/1911/18797.


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