Introduction

The Terahertz research is an advanced research that requires knowledge in multiple fields of study. Such fields include but not limited to: geometric optics, Fourier optics, nonlinear optics, laser optics, ultrafast science, plasma physics, crystallography, electronical and computer engineering, etc.

We understand that it is impossible to be a polymath in every single field mentioned above. Therefore, we offer this Terapedia for beginners and people of interests to have a basic understand to our research.

Basics

THz radiation refers to the electromagnetic radiation that oscillates around 1×10¹² times per second: 1 THz = 1×10¹² Hz. It is a radiation that is not visible to human eyes.

The THz radiation interval is roughly defined to be within 0.1 – 10 THz (0.03 – 3 mm) by the International Telecommunication Union, although there have been articles claiming the upper boundary to be 30 THz or more. Since the practice of THz research is varied among different scientists in optics, physics, chemistry, and engineering, it is important to address
all commonly accepted parameters that are equivalent to 1 THz:

From the electromagnetic frequency spectrum shown above, one can easily tell that THz radiation is in between the optical frequency waves and electronic waves. This gives rise to the difficulties and challenges of treating THz radiation, since one needs both optical and electronic strategies to measure and detect THz radiation.