Laser Pulse Generating Light Emitting Plasma Filamentin Here is your first Forum Mon Aug 01, 2016 8:55 pm
by Eyes123456 • 33 Posts
Laser Pulse Generating Light Emitting Plasma Filament
At the Massachusetts Institute of technology and other local researchers found a new method, using mid infrared 3000mw laser pointer will be the development of air environment in the molecular region into charged gas or plasma is composed of light-emitting filament. This new approach can enable remote environmental monitoring of chemicals with high sensitivity to detect a wide range of possible.
This new system uses the mid infrared ultra fast pulsed 5000mw green laser system to produce the luminous filament, the filament's color can reveal the chemical fingerprint of different molecules. The findings reported in this week's "due to" magazine and the author of the article is at the Massachusetts Institute of Technology Research Laboratory of electronics and chief researcher of Kyung-HanHong, and other seven from the Massachusetts Institute of technology, in Binghamton, New York, and Hamburg, Germany, research personnel.
Hong explains that the filament, which is produced by a laser at the wavelength of the near infrared part of the electromagnetic spectrum, has been widely studied for its good applications in the fields of laser ranging and remote sensing. The filament phenomenon, which is produced by a high power Laser pointer, can be used to counter the diffraction effect of the laser beam passing through the air. When the power level reaches a certain point, the filament effect is generated, and they provide a self guiding channel to keep the laser beam tightly focused.But for the detection of a wide variety of biochemical compounds and air pollutants, the mid infrared (mid-IR) wavelength than near infrared can provide a better effect. However, until now, researchers in the open air to produce a mid infrared filament attempts have almost no success.Only one research team has successfully produced a mid IR laser filament in the air, but it is done at a much slower rate of about 20 pulses per second. And in this new work, the rate of use of 1000 pulses per second, which is the first time to achieve the required rate of the actual detection tool, Hong said.
"People want to use this technology to detect chemicals that are a few miles away," says Hong, but they have a lot of difficulty in implementing such a system. One of the keys to the success of the team is the use of a high power femtosecond burning laser pointers with only a pulse length of only 30 (a femtosecond = 10 million 1/100000000 sec). The longer the wavelength, the stronger the diffraction effect is, the higher the laser peak power required to produce the desired filament effect, he said. But the team used a femtosecond laser, coupled with the so-called parametric amplifier, to provide the power needed for the task. This new laser system has been developed in the last few years with FranzX.Kaertner and other team members in Hamburg. Hong said that the device in the mid infrared wavelengths produced the world's highest peak power levels, and its peak power reached 100 billion watts (GW).Using spectral broadening of mid infrared laser filament effect, through the detection of filament the exact color. "We can detect molecular almost anything you want," Hong says, including a variety of biological harmful substances and pollutants. In the mid infrared range, the absorption spectrum of the specific chemical can be easily analyzed.
So far, the experiment has also been limited to short distances in the laboratory, but the team believes that, with further development, there is no reason for the same system will not work on a green laser pointer scale. "This is just a proof of principle demonstration," Hong said.This study "is one of the most early studies of self - guided laser pulses in the air," said PavelPolynkin, an associate professor of optics at the University of Arizona, who was not involved in the work. "As to whether there will be new and exciting applications, time will give the answer."