PTB Terahertz calibration satisfies US laser manufacturer
Friday, November 6, 2009 - 06:00
in Physics & Chemistry
Terahertz radiation still lies in a metrological no man's land - a metrology gap. The Physikalisch-Technische Bundesanstalt (PTB) can now close this gap. For the first time, a commercial Terahertz laser was traced back to the international system of units (SI) by measuring its output power absolutely. PTB achieved this success with a power meter which had been calibrated beforehand against a cryogenic radiometer, Germany's primary standard for power measurement of electromagnetic radiation. Therefore, this laser, namely a SIFIR-50 manufactured by the US company Coherent Inc., is the first THz laser in the field with a reliably proven output power enabled by a novel calibration capability set up at the PTB...