Image quality in infrared spectroscopic imaging can be improved dramatically by an appropriate redesign of instruments. Theoretical insights obtained from modeling light propagation through the entire instrument have guided a design that has resulted in high-definition imaging wherein the important image details are now accessible. This has improved the accuracy of cancer detection using infrared spectroscopic imaging.
High resolution mid-infrared spectroscopic imaging was demonstrated recently in our paper that received recognition from various scientific communities. We presented a new way of understanding and designing infrared imaging instruments based on a modular approach that utilizes an operator formalism. This technique of instrument construction provides an intimate connection between theory and experiment. There is a direct, one-to-one correspondence between an optical component (like a lens) in an experiment and an operator in the theory. Replacing one component in an experiment is equivalent to replacing one operator and vice versa. Therefore, changes to an instrument design can be understood and analyzed easily and this rapid feedback loop between theory and experiment enables the design of significantly better instruments. We demonstrated the power of these ideas by developing a high-definition mid-infrared spectroscopic imaging instrument which provides significantly higher image detail than in current commercial instruments. The figure on the left is an example of data from such an instrument where a chemical map of tissue is obtained using our proposed instrument. This provides excellent tissue detail by the press of a button without laborious chemical stains that are normally required.