Through the development of new scientists of National Institute of Standards and Technology (National Institute of Standards and Technology - NIST) United States, which used a nanoscale coating of directional radiation power meter, laser power calibration system will be faster, easier and more accurate.

The results of the development are published in the journal Optics Letters (Black optical coating for high-power Laser measurements from carbon nanotubes and silicate).

The new power meter, the last full test at the U.S. Air Force Base, will be used to measure radiation 10 kilowatt laser systems. Focused laser radiation of 10 kW more than a million times stronger than the solar radiation reaching the Earth's surface. To date, the power meter NIST, just as lasers, the power which they were intended to measure, are not portable and funtsionirovali very slowly. The new power meter - much smaller - about the size of the pot cooker. The new design facilitates the process of measuring device.

The key innovation here has been deposited at the head of the receiver of radiation coating of carbon nanotubes, which conduct heat hundreds of times better than traditional primenyamye materials.

The proposed design for measuring the power beam of laser radiation to the head of the reception, being the shrinking copper cone. Rotating mirror at the input laser radiation distributes uniformly in the area of the conical surface, which gives an even distribution of heat. Admitting the surface of the cone is absorbing coating of mnogostennyh carbon nanotubes in relation of potassium silicate (liquid glass). In itself, receiving the meter head is located in a water bath. Coverage of the carbon nanotubes have very high capacity to absorb radiation in a certain range of wavelengths and absorbing radiation, is heated and, therefore, heats the water in the cooling water jacket. By changing the water temperature is judged on the power of radiation.

NIST develops standards and optical devices for measuring and maintaining for the past several decades. In recent years, NIST researchers have experimented with many kinds of absorbing coatings based on nanotubes, because these coatings offer an unusual combination of desirable properties, including the maximum absorption of radiation. In particular, it was discovered that carbon nanotubes mnogostennye absorb radiation better than odnostennye nanotubes. The new device used coverage resulting from these studies with a high absorbency, high thermal stability and durability. Researchers continue to work on the selection of coatings based on nanotubes: the main task today is to create an absorbing coating, which not only has all the necessary mechanical, optical and thermal properties, and easily applied mechanically on the surface of the desired structure and shape, such as enamel paint . Many of nanopokryty developed by NIST, has already been transferred to industry.

Development of a new power meter was funded by the U.S. Air Force.

Eugene Birger

Source (s): http://www.nist.gov/