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Optical Metrology Laboratory

The NREL Optical Metrology Laboratory at the Solar Radiation Research Laboratory ensures that optical radiation resource measurement equipment is calibrated to national or international standards to ensure the quality and traceability of data.

NREL considers optical radiation to range from 250 nanometers (nm) to 2,500 nm and to include the ultraviolet (250–400 nm), visible (400–750 nm), near-infrared (750–1,100 nm), and shortwave infrared (1,100–2,500 nm) ranges.

The Optical Metrology Laboratory provides National Institute of Standards and Technology (NIST)-traceable measurements for:

  • Spectral irradiance and radiance (250–2,400 nm) scale realizations
  • User spectroradiometer calibrations
  • Natural sunlight and artificial source spectral distribution measurements
  • Indoor and outdoor solar ultraviolet (250–400 nm), photosynthetically active radiation (400–700 nm), and photometric calibrations
  • Spectral reflectance and transmission testing.

In addition, the lab provides pulsed/continuous light source characterization that is traceable to NIST standards.

The Optical Metrology Laboratory offers a range of specialized equipment:

  • ASD, Inc., FieldSpec Pro fast (200–millisecond acquisition), wide-range (350–2,400 nm) spectroradiometer
  • Optronic Laboratories OL-750 scanning spectroradiometer with a wide wavelength range (280–2,400 nm) and pulse integration capability
  • Optronic Laboratories OL-756 ultraviolet double monochromator spectroradiometer with a 250–800 nm spectral range
  • NREL's Pulse Analysis Spectroradiometer System (PASS), which captures light pulse profiles and determines spectral irradiance at any position within a pulse profile
  • Portable, spectrally calibrated light sources that consist of constant-output incandescent lamps with measured spectral distribution (require AC power)
  • 150-watt mercury/xenon solar simulator
  • Emission line sources for wavelength calibration, including mercury, xenon, neon, and argon penlights and wavelength emission documentation
  • NIST-calibrated filter glasses (transmission and wavelength) and reflectance standards
  • Integrating spheres and fiber-optic probes for spectroradiometer systems
  • Filters, including glass and metal neutral density, wide and narrow passband, cut-on and cut-off glass, and interference types.


Afshin Andreas

Senior Scientist | 303-384-6383