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Laser power meter comparison at far infrared wavelengths and terahertz frequencies



John H. Lehman, Marla L. Dowell, Nina P. Basta, Kerry N. Betz, Erich N. Grossman


We have evaluated the responsivity of seven different detectors compared to an electrically calibrated photo-acoustic detector at 119 υm (2.5 THz) and 394 υm (0.76 THz) laser wavelengths. Among the detectors is an electrically calibrated thermopile having a vertically aligned carbon nanotube array (VANTA) as the absorber. The measurement results indicate that the nanotube-coated detector has relatively high and uniform responsivity compared to the photoacoustic detector. We document the relative uncertainty of these measurements along with the calibration factor of each detector.


carbon nanotubes, far infrared, laser radiometry, photoacoustic detector, pyroelectric detector, terahertz, thermopile, uncertainty


Lehman, J. , Dowell, M. , Basta, N. , Betz, K. and Grossman, E. (2012), Laser power meter comparison at far infrared wavelengths and terahertz frequencies, Metrologia, [online], (Accessed April 16, 2024)
Created August 1, 2012, Updated November 10, 2018