What are terahertz sources?

A Globar source is a resistively heated silicon carbide rod that operates at high temperature. A Globar source emits over an extremely wide spectral region (into the THz region) but with a very weak output power of the order of picowatts. Globars are used to light gas ovens.

How fast is a terahertz?

Terahertz (unit), a unit of frequency, defined as one trillion (1012) cycles per second or 1012 hertz.

What is a terahertz pulse?

Pulsed terahertz radiation is generated with femtosecond lasers. An ultrashort laser pulse generates a current transient in the emitter and as a result, an electromagnetic wave packet with a broad spectrum in the terahertz range.

How does THz TDS work?

THz-TDS measures the electric field of a pulse and not just the power. Thus, THz-TDS measures both the amplitude and phase information of the frequency components it contains. Even when measuring only the power reflected from a sample, the complex optical response constant of the material can be obtained.

How do you measure terahertz?

The electrical field of the terahertz pulses is measured in a detector that is simultaneously illuminated with an ultrashort laser pulse. Two common detection schemes are used in THz-TDS: photoconductive sampling and electro-optical sampling.

How are terahertz detectors used in everyday life?

Spectroscopy in this frequency range has additional applications in industrial processing and remote identification of chemicals. We are using our unique capabilities in terahertz detectors, optics, metrology methods, and test-beds in these applications. Passive millimeter-wave image of concealed contraband (handgun and ceramic knife).

What are the applications of imaging in the terahertz range?

Imaging in the terahertz frequency range enables the detection of concealed weapons and other contraband (e.g., explosives under clothing) without the use of ionizing radiation. Spectroscopy in this frequency range has additional applications in industrial processing and remote identification of chemicals.

How are terahertz sources used in free space?

The ABC source is a key component of a long-range plan to establish traceability for free-space radiometric power quantities where none currently exists. Developed and demonstrated an ultra-wideband, sub-millimeter-wave/terahertz detector array for use in contraband detection with Valtion Teknillinen Tutkimuskeskus (VTT) of Finland.

How are lasers used to detect THz radiation?

Two distinct methods exist to generate and detect THz radiation using ultrafast laser systems. In the Schmuttenmaer group we utilize two different techniques: photoconductive antennas and non-linear optics. The mechanisms for terahertz generation and detection using those two techniques are described below.

What are terahertz sources? A Globar source is a resistively heated silicon carbide rod that operates at high temperature. A Globar source emits over an extremely wide spectral region (into the THz region) but with a very weak output power of the order of picowatts. Globars are used to light gas ovens. How fast is…