SALEM, N.H., Oct. 10, 2012 — GPD Optoelectronics Corp.’s 2-mm over 2-mm InGaAs “sandwich” detector assembly is designed for noncontact optical pyrometry. The company uses a customized 1.7-µm cutoff wavelength sensor for the top InGaAs photodiode. The bottom InGaAs photodiode’s spectral response can be selected from a 1.7- to 2.6-µm cutoff wavelength, depending upon temperature requirements. This classic geometry applies the “ratio principle” temperature measurement. The advantages are: Temperature measurements are independent of the target’s emissivity over wide ranges, the target area can be smaller than the detector area, and measurements are unaffected by dust and other contaminants in the field of view.