The name is absent

40

Chapter 5

Terahertz spatial light modulator (SLM)

In the past decade, much research effort has been focused in the area of THz gen-
eration and detection [74,75], while many functional devices for direct manipulation
and processing of THz radiation are still lacking. One example is a spatial light
modulator (SLM) for THz beams. SLMs allow the optical or electrical control of the
spatial transmission (or reflection) of an input light beam, and thus the ability to
redirect or encode information in a wave front. Such devices are key components for
many optical and optoelectronic systems, with applications in optical processing, op-
tical interconnections, image display and real-time beam steering [76,77]. Real-world
examples of SLM include liquid crystal display (LCD) projector, and the Texas In-
struments (TI) digital micromirror device (DMD) [78]. This technology, if extended
to the THz region of the spectrum, can benefit exciting applications in THz imaging
and communications [79,80]. For instance, the major speed limitation for the single-
pixel THz imaging system in Chapter 4 is the slow translation of random patterns on
PCBs from one to another. A high-speed SLM would be ideal for encoding random
spatial patterns into the wave front of a THz beam for this imaging application.

The construction of a THz SLM requires an array of small THz devices that can
independently control the transmission of a THz beam at their respective array posi-
tions. Traditional technologies for SLMs in the optical regime [76,81], which use liquid
crystals, magneto-optic effects or deformable mirrors, do not operate efficiently in the
THz regime because of the lack of materials with the desired THz response and/or the

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