Researchers have shown that distorted photons (Nondestructive Mid-Infrared Imaging) can be used to improve penetration depth using optical coherence tomography (OCT) in more scattered materials. This method is a method for generating medium infrared wavelength OCT and can be useful for non-destructive testing and analysis of materials such as ceramics and color samples.
OCT is a non-destructive imaging method that provides detailed 3D images of underground structures. OCT is usually performed with visible or near-infrared wavelengths because light sources and detectors for these wavelengths are readily available. However, these wavelengths do not absorb well in highly dispersed or porous materials. In the journal Optica, the journal Optical Society (OSA) for high-impact research, Aron Vanselow and colleagues from Humboldt-Universität zu Berlin in Germany, together with colleagues from the Research Center for Non-Destructive Testing GmbH in Austria. a proof-of-concept experiment for mid-infrared OCT based on ultra-wideband distorted photon pairs. They show that this method can create high-quality 2D and 3D images from multiple scattered samples with a relatively compact, rectilinear optical setup.
“Our approach eliminates the need for broadband mid-infrared sources or detectors, which makes it difficult to develop practical OCT systems that operate at these wavelengths,” Vanselow said. “This is one of the first real-world applications where related photons compete with conventional technology.”
This technique (Nondestructive Mid-Infrared Imaging) can be useful for many applications, including the analysis of complex coatings used in aircraft and automobiles, as well as in the control of coatings used by pharmacists. It can also provide detailed 3D images that can be used to preserve art. Purchasing in quantum mechanics
When photons are involved, they act as if they are directly interacting with each other. This quantum mechanical phenomenon is important in many applications of quantum technology that are evolving, such as quantum sensing, quantum communication, or quantum computation.
For this technique, researchers have developed and implemented a nonlinear crystal that generates broadband photon pairs with different wavelengths. One of the photons has a wavelength that can be easily detected by standard equipment, while the other photon is in the mid-infrared range, making it difficult to identify. When difficult-to-detect photons illuminate the sample, it adjusts the signal in a way that is only measured with easily detectable photons. “Our technology makes it easy to obtain useful measurements in the traditionally difficult wavelength control due to technological challenges,” said Sven Ramelow, who led and led the research. “In addition, the lasers and optics we use are less complex and compact, robust, and cost-effective than those used in today’s mid-infrared OCT systems.”
Display in low light
To demonstrate this technique, the researchers first confirmed that the performance of their optical settings was consistent with theoretical predictions. They found that they could use six orders of magnitude less light to achieve the same signal-to-sound ratio as some conventional mid-infrared OCT systems, which are newer.
“We were positively surprised that we didn’t see any sound outside the actual quantum sound of the light itself,” Ramelow said. “It also explains why we can achieve a good signal-to-sound ratio with less light.”
The researchers tested their settings on a variety of actual samples, including more scattered color samples. She also researched two 900 micrometer thick alumina ceramic stacks with laser milled microchannels. Mid-infrared light allows researchers to capture in-depth information and perform a complete 3D reconstruction of the channel structure. The pores of alumina ceramics make this material useful for drug testing and DNA detection, but they also scatter the wavelengths traditionally used for OCT.
Researchers have already begun working with industry partners and other research institutes to create a compact OCT sensor head and a complete system for a pilot commercial application.
