Inside the Laboratory: The Gamez Group at Texas Tech

"Inside the Laboratory" is a joint series with LCGC and Spectroscopy, profiling analytical scientists and their research groups at universities all over the world. This series spotlights the current chromatographic and spectroscopic research their groups are conducting, and the importance of their research in analytical chemistry and specific industries. In this edition of “Inside the Laboratory,” Gerardo Gamez, a Professor and Graduate Advisor at Texas Tech University, discusses how compressed sensing spectroscopic techniques are used in his laboratory (1).

This interview was conducted as part of our coverage of the Winter Conference on Plasma Spectrochemistry, which is taking place from January 9–17^th in Tucson, Arizona (2).

Spectroscopy: Can you talk about the projects the Gamez Group at Texas Tech is working on that involves using compressed sensing spectroscopy techniques?

Gerardo Gamez: Compressed sensing basically proposing an alternate way to sample and enable much faster analysis. For example, when we take a picture with our phone, we could save it as a raw file, which takes a lot of memory, or we could save it as a JPEG file which requires much less memory. However, when we open them both, they're virtually indistinguishable, right? Now, that compression is possible because there's a lot of redundant information. Compressed sensing basically allows us to do that compression during the acquisition, so we don't have to spend all those resources sampling the data. That lowers the requirement and the number of samples, and then we can make it faster. We developed this technique called glow discharge optical emission coded aperture elemental mapping, or GOCAMP for short. We combined GDOES elemental mapping with compressed sensing and hyperspectral imaging (HSI) to enable collecting full multielemental maps in a fraction of a second.

This resolves the issue of using two-dimensional (2D) array detectors. The cameras that we use are 2D, but we need to collect a three-dimensional (3D) data cube. Traditional techniques require at least scanning one dimension, which takes a little bit longer. And when it comes to the glow discharge, since we were talking about sputtering the sample into the plasma, we're basically consuming the sample as we're analyzing it. For example, in the case of nanoscale materials, we may consume the whole sample before reaching the other end of the window we're scanning. Instead, what we're doing for this compressed sensing HSI is that we are spatially encoding the image, and we do that by passing it through a mask with open and closed apertures. We also then disperse the light on the image.

This allows us to basically fold the 3D hyperspectral data cube to 2D to collect simultaneously, and then we can decode it in the software since we know the code, but we can also use hyperspectral compress sensing recovery to recover parts of the image that were blocked. And so, we can basically reconstruct the full elemental maps and collect them in a fraction of a second. This is really faster than any traditional or state-of-the-art techniques, and so in this case, it can be potentially transformative for characterization of, for example, monoscale materials.

This video clip is the third part of our conversation with Gamez. To stay up to date on our coverage of the Winter Conference on Plasma Spectrochemistry, click here.

References

1. Texas Tech University, Dr. Gerardo Gamez. TTU.edu. Available at: https://www.depts.ttu.edu/chemistry/Faculty/gamez/ (accessed 2026-01-06).
2. IASA, Winter Conference on Plasma Spectrochemistry. IASA. Available at: https://iasa.world/winter-plasma-conference (accessed 2026-01-06).