MY NOTE: YET ANOTHER POST, THAT'S NOT DIRECTLY ABOUT TERAHERTZ, BUT IS AN INTERESTING ADDITION TO EARLIER POSTS ABOUT THE USE OF TERAHERTZ, TO CREATE INVISIBILITY CLOAKING
http://www.newkerala.com/news/2011/worldnews-86449.html
Washington, Oct 13 : US researchers have successfully demonstrated a so-called “history editor” cloaking device that is able to “hide” a singular event in time for 20 trillionths of a second.
In a feat of Einstein-inspired physics, Moti Fridman and his colleagues sent a beam of light traveling down an optical fiber and through a pair of so-called “time lenses.”
Between these two lenses, the researchers were able to briefly create a small bubble, or gap, in the flow of light. During that fleetingly brief moment, lasting only the tiniest fraction of a second, the gap functioned like a temporal hole, concealing the fact that a brief burst of light ever occurred.
To test the performance of their temporal cloak, the researchers created pulses of light directly between the two lenses. The pulses repeated like clockwork at a rate of 41 kilohertz. When the cloak was off, the researchers were able to detect a steady beat. By switching on the temporal cloak, which was synchronized with the light pulses, all signs that these events ever took place were erased from the data stream.
Unlike spatial optical cloaking, which typically requires the use of metamaterials (specially created materials engineered to have specific optical properties), the temporal cloak designed by the researchers relies more on the fundamental properties of light and how it behaves under highly constrained space and time conditions.
The area affected by the temporal cloak is a mere 6 millimeters long and can last only 20 trillionths of a second. The length of the cloaked area and the length of time it is able to function are tightly constrained—primarily by the extreme velocity of light.
Cloaking for a longer duration would create turbulence in the system, essentially pulling back the curtain and hinting that an event had occurred.
Also, to achieve any measurable macroscopic effects, an experiment of planetary and even interplanetary scales would be necessary.
The study will be presented at the Optical Society’s (OSA) Annual Meeting, Frontiers in Optics (FiO) 2011.
http://www.newkerala.com/news/2011/worldnews-86449.html
Washington, Oct 13 : US researchers have successfully demonstrated a so-called “history editor” cloaking device that is able to “hide” a singular event in time for 20 trillionths of a second.
In a feat of Einstein-inspired physics, Moti Fridman and his colleagues sent a beam of light traveling down an optical fiber and through a pair of so-called “time lenses.”
Between these two lenses, the researchers were able to briefly create a small bubble, or gap, in the flow of light. During that fleetingly brief moment, lasting only the tiniest fraction of a second, the gap functioned like a temporal hole, concealing the fact that a brief burst of light ever occurred.
To test the performance of their temporal cloak, the researchers created pulses of light directly between the two lenses. The pulses repeated like clockwork at a rate of 41 kilohertz. When the cloak was off, the researchers were able to detect a steady beat. By switching on the temporal cloak, which was synchronized with the light pulses, all signs that these events ever took place were erased from the data stream.
Unlike spatial optical cloaking, which typically requires the use of metamaterials (specially created materials engineered to have specific optical properties), the temporal cloak designed by the researchers relies more on the fundamental properties of light and how it behaves under highly constrained space and time conditions.
The area affected by the temporal cloak is a mere 6 millimeters long and can last only 20 trillionths of a second. The length of the cloaked area and the length of time it is able to function are tightly constrained—primarily by the extreme velocity of light.
Cloaking for a longer duration would create turbulence in the system, essentially pulling back the curtain and hinting that an event had occurred.
Also, to achieve any measurable macroscopic effects, an experiment of planetary and even interplanetary scales would be necessary.
The study will be presented at the Optical Society’s (OSA) Annual Meeting, Frontiers in Optics (FiO) 2011.
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