The name is absent

by modulating the THz beam with a set of random patterns. The system uses a
weighted sum of all of the image pixels as each measurement, with weights of zero
and 100% at random pixel locations [10]. This simple binary filtering can be easily
implemented optically, by randomly blocking a subset of the pixels in the image and
collecting the remaining light with a single lens.

Thanks to the CS theory, both systems already have benefits in imaging speed due
to the reduced number of measurements required for reconstruction. The single-pixel
CS imaging system, in principle, can achieve image acquisition at even higher speed
if completely dispensed with all mechanical moving parts. However, the current tech-
nology has not yet developed a fast spatial light modulator (SLM) for THz beams
to modulate the random patterns. Therefore, the second part of this thesis addreses
the design and construction of high speed spatial terahertz modulators using active
terahertz metamaterials [11,12]. After incorporating this device into the single-pixel
CS imaging system, we no longer need to rely on mechanical moving parts as in tradi-
tional raster scanning systems. This system will still preserve the superior detection
sensitivity of single-point detectors such as photoconductive antennas (rather than
the lower sensitivity provided by existing multi-pixel arrays). As a result, we antic-
ipate to achieve efficient terahertz imaging at a rate compatible with video imaging
with simple, cost-effective hardware.

1.2 Scope of this thesis

Chapter 2 provides the background for the two major topics in this thesis, terahertz
imaging and compressive sensing. Chapter 3 and 4 demonstrate the performance
of the CS Fourier THz imaging system and the single-pixel CS THz imaging system
respectively, through experimental results based on both imaging schemes. Chapter 5

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