Avian Technologies offers four rare earth oxide glass filters; holmium oxide glass, didymium oxide glass, a multiple oxide filter, and a long wavelength filter. All filters have peaks useable in the UV-Vis-NIR; didymium oxide is typically used in the visible region of the spectrum, while multiple oxide, holmium oxide, and long wavelength filters are used over the entire UV-Vis-NIR range.
Multiple Oxide Filter (WCT-2065)
Avian Technologies, working in conjunction with the Analytical Chemistry Division of NIST, offers a wavelength calibration standard for the Vis-NIR spectral range.
WCT-2065 is the equivalent of NIST SRM-2065. This standard is useful in the calibration of NIR spectrophotometers, both dispersive and Fourier transform, in the 400-2200 nm wavelength range. The filter material is glass made with a combination of rare earth oxides, including holmium oxide, samarium oxide, ytterbium oxide, and neodymium oxide in a base glass containing oxides of lanthanum, boron, silicon, and zirconium.
The standard is also available in a reflectance version.
Holmium Oxide & Didymium Oxide Filters
Avian Technologies also offers Holmium Oxide and Didymium Oxide filters.
Long Wavelength Range Wavelength Calibration Standard
This Avian Technologies standard combines NIST 2065 glass (Avian Technologies WCT-2065) and polystyrene to give a wavelength standard with useable peaks beyond 2300 nm, to meet the calibration needs for modern portable near-infrared spectrometers.