Method for fabrication of a multivariate optical element

A method for fabricating a multivariate optical element comprising:

• selecting a lamp spectrum and bandpass filter spectrum;
• obtaining a spectral characteristics vector to quantify the concentration of a component in a sample;
• obtaining a target spectrum from the lamp spectrum, the bandpass filter spectrum, and the spectral characteristics vector;
• selecting a maximum number of layers to be formed on a single face of an optical element;
• selecting a number of layers to be formed on the single face of the optical element less than the maximum number of layers;
• performing an optimization routine by adjusting an index of refraction and thickness of each of the number of layers until an error between a model spectrum and the target spectrum is less than a tolerance value, or a number of iterations is exceeded, wherein the optimization routine applies a first detector proportionality constant;
• reducing the number of layers if the error is less than the tolerance value;
• stopping the procedure if the number of iterations is exceeded to change the tolerance value;
• in response to the optimization routine, fabricating the optical element;
• and
• adjusting the first detector proportionality constant to a second detector proportionality constant, thereby calibrating the fabricated optical element.