By Dr. Ephraim Greenfield, CTO, Ophir Optronics
Ophir Photodiode sensors use silicon, germanium and InGaAs sensors together with built in and removable filters. The spectral response of these type of sensors vary widely with wavelength. When used with our smart displays or PC interfaces, the sensitivity factor for the relevant wavelength is automatically set when the user inputs the laser wavelength.
However, there are cases where this simple inputting of the laser wavelength are not applicable, in particular if the source is not a single wavelength. The source may be a combination of several wavelengths, or a wavelength band or a broadband source.
For the information of such users, we present here the relative spectral response of these sensors both with the removable filter installed and not installed. The user can then set the wavelength on the display to a convenient value and by calculation, using these graphs, correct for the actual multiple wavelengths or wavelength band he has.