Methods and systems using photonic crystal-based integrated computational elements

A method, comprising:

• selecting a desired transmission spectrum for an integrated computational element (ICE):
• identifying a photonic crystal (PhC) structure having a transmission spectrum comparable to the desired transmission spectrum:
• obtaining the transmission spectrum for the PhC structure;
• determining a predictive power of a PhC-based ICE for a characteristic of a sample with the obtained transmission spectrum and a database of spectra for calibrated samples;
• adjusting the transmission spectrum of the PhC structure to improve the predictive power of the PhC-based ICE;
• and
• fabricating the PhC structure for the PhC-based ICE when the predictive power surpasses a pre-selected threshold.

An integrated computational element (ICE), comprising:

• a photonic crystal (PhC) structure having an optical input side configured to receive interacted light and an optical output side configured to receive an optical output, the PhC comprising:
• a medium having a first index of refraction;
• and
• a substrate embedded in the medium, the substrate having a second index of refraction and at least one geometric feature, wherein
• the at least one geometric feature is selected based on an output spectrum resulting from the optical output side, and wherein
• the optical output has an amplitude proportional to a scalar product of the interacted light and a regression vector for a characteristic of a sample being analyzed.