Recent Progress on Calibration of Spectroradiometers using Tunable Lasers

To reduce calibration uncertainties of spectroradiometers, we developed a detectorbased method for calibrating spectroradiometers directly (one-step) against transfer-standard trap detectors using a tunable laser. Recently, we conducted more research on spectroradiometer’s wavelength calibration and the uncertainty was reduced to approximately 0.25 % (k = 2), which is much smaller than that using the conventional calibration method based on transfer-standard lamps. The calibrated spectroradiometer is also a new transfer-standard detector for spectral irradiance or radiance scale.