This PhD dissertation presents new photonic architectures and devices for generation and detection of sub-THz and THz waves.

The traditional issues of photonic THz generation are overcome through the design and implementation of a photonic THz synthesizer with frequency resolution, phase noise and stability performance more than one million times better than currently commercially available state-of-the-art photonic systems, and matching or even surpassing this performance with respect to state-of-the-art electronic THz generation systems. Additionally, the advantages of photonic techniques are mantained, namely, remote distribution

using optical fiber, whole frequency range tunability and the use of telecom optical devices and components.

The barely explored field of Electro-Optical (EO) heterodyne THz detection, which permits higher sensitivity and the remote distribution of THz Local Oscillator (LO) signals with very low losses through several kilometers, is also covered in this document. The photonic THz synthesizer developed in this thesis is employed together with a novel THz detector acting as EO THz mixer to demonstrate EO heterodyne detection under zero bias voltage and with ultrahigh LO frequency resolution for the first time.

The results reported in this doctoral thesis validate the use of photonic techniques for state-of-the-art THz generation and for the implementation of remote EO heterodyne receivers capable of working unbiased.