Researchers at NIST have developed vertically aligned carbon nanotube arrays (VANTAs) that can accurately measure absolute output power for terahertz lasers. These nanotube arrays, which are 1.5 mm long, absorb nearly all light in the terahertz range, making them promising coatings for laser power detectors.
The research is part of NIST’s efforts to establish the first U.S. reference standards for calibrating terahertz lasers, which operate in the 100 micrometer to 1 millimeter wavelength range. Terahertz radiation has applications in concealed weapons detection, package inspection, and imaging skin tumors.
VANTAs have several advantages over other black coatings, including being easy to handle, visible without a microscope, and having good thermal properties. NIST is currently building a terahertz laser and a thermopile detector for routine measurements, with plans for further research to design detectors that could be used as reference standards.
Keywords: VANTA, terahertz lasers, carbon nanotube arrays
