Study led by ECE student featured in a special issue of Applied Spectroscopy

A systematic methodology for optical design considerations in infrared imaging microscopes that is supported by the mathematical foundations is helping researchers efficiently design new-generation microscopes for target specific applications such as cancer and other disease diagnosis. The study is authored by Illinois ECE student Yamuna Phal and Professor Rohit Bhargava, and post-doctoral fellow Kevin Yeh at Beckman Institute.

Discrete frequency infrared imaging is an emerging tool that is transforming the practice of microspectroscopy for label-free diagnosis applications. However, a methodical attempt to summarize the optical design steps is missing. “Unlike optical microscopy, infrared regime spans broader wavelength range, and this makes the task of designing imaging microscopes notoriously painstaking. Furthermore, aligning invisible light is another challenge that needs to dealt with," said Phal.

In the study, which was featured as a Focal Point Review for Applied Spectroscopy, the authors systematically describe the evolution of IR microscopes, provide rationales for design choices, and catalog some major considerations for each of the optical components in an imaging system.

The study covers the evolution and development of Discrete Frequency Infrared (DFIR) technology and its maturation into state-of-the-art fast and high SNR systems. It presents characterization techniques of some typical DFIR spectroscopic imaging systems in point-scanning configuration that can acquire rapid absorbance measurements. This work provides a tool for future designs and evaluation of DFIR microscopy systems that have major implications for revolutionizing DFIR technology.