QUANTUM ELECTRONICS ---     THz RADIATION EMITTERS

THz emitters operate in a plasmonic regime. This concept is applicable to all fractal geometries such as Sierpinski and Apollonian fractals.  There is presently an enhanced interest in generation of intense, coherent terahertz (THz) beams

Spanning the so-called “Terahertz gap” range of the electromagnetic spectrum from ~100 GHz to 10 THz. As yet, there are no compact semiconductor sources of THz radiation within this frequency range. The largest breakthrough in generation of coherent and broadband pulses of electromagnetic radiation of THz frequency range is achieved by using ultra short laser pulses illuminating semiconductor surfaces [1-4]. There are quite a number of different physical mechanisms that are employed for this generation; they could be divided into three groups.

Coherent THz pulses are generated by the semiconductor illuminated by femtosecond laser pulses

Due to:

·         nonlinear optical interaction between the light pulses and the material,

·         photocurrent surge perpendicular to the illuminated surface, and

·         lateral photocurrent effect using wideband antennae integrated with photoconductors made

http://www.dtic.mil/dtic/tr/fulltext/u2/a445370.pdf

However, pressure to develop new terahertz sources arose from two dramatically different groups—ultrafast timedomain spectroscopists who wanted to work with longer wavelengths, and longwavelength radio astronomers who wanted to work with shorter wavelengths. Today, with continuous-wave (CW) and pulsed sources readily available, investigators are pursuing potential terahertz-wavelength applications in many fields.

http://www.aip.org/tip/INPHFA/vol-9/iss-4/p27.html

Ziyad Alamri
post #3