Periodic Reporting for period 2 - SYNTOH (Synthetic Optical Holography) Reporting period: 2018-01-11 to 2019-01-10 Summary of the context and overall objectives of the project Microscopy is an indispensable tool in research, medicine and industry that enables the inspection of objects that are otherwise too small to see with the naked eye. But detailed view on biological objects, for example, is tremendously important: Microscopy allows to identify structure within cells and tissues, which made it a vital instrument for modern molecular and cell biology. The 2014 Nobel price award to Betzig, Moerner and Hell for super-resolved fluorescence microscopy is a clear signal that continuous development in the field of microscopy is recognized and essential for research that relies on microscopy.This project, SYNTOH, developed and facilitated phase imaging, an emerging imaging modality in microscopy with applications in biology, medicine and manufacturing. In a typical microscopy application, contrast is generated by light absorption in the sample, which however requires staining to reveal structure in biological specimen. But light also experiences subtle shifts in the light wave’s phase as it passes the specimen. This effect yields rich information on the sample, which, however, is typically lost in recording process. The phase information can be retrieved by phase imaging. However, current methods are slow or expensive.In the framework of SYNTOH, we developed synthetic optical holography as a core technology. It provides a fast, technological simple and cost effective way to perform phase imaging in confocal microscopy. We verified our technology by imaging relevant biological specimen, and additionally we developed and demonstrated a concept of an add-on module for existing microscope setups.Furthermore, we have investigated a particular application of phase imaging for cancer diagnosis. An estimated 3.7 million new cases of cancer are diagnosed in Europe each year. Higher precision in prediction of clinical outcomes are needed for more effective decision making. This project has investigated how phase imaging can provide a new view in microscopy-based investigation of cancer.Synthetic optical holography was also investigated for nano-imaging applications. Near-field microscopy is an emerging technology for nanoscale-resolved infrared imaging of surfaces, and has been tested in a variety of applications with promising results: conductivity mapping in semiconductors, plasmon mapping in graphene and identification of protein complexes in biomedical imaging. However, current technology is limited in speed. The holographic approach of Synthetic Optical Holography (SOH) can lead to rapid imaging and to multispectral imaging. The conclusion of this project is that synthetic optical holography was demonstrated for confocal microscopy and key applications such as label-free cell and tissue imaging were demonstrated. This project now makes this technology available for users of confocal microscopy. It is cost effective and easy to operate, and yields clearer phase imaging owing to suppression of halo and speckle artifacts. Further, we developed a microscope platform that combines phase and infrared contrast for augmented and automated histopathology. Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far We have developed a universal system extension based on synthetic optical holography. It allows for phase imaging in existing confocal microscopes without requiring modifications to the setup. This opens the way to cost-effective, easy-to-install drop-in solutions. We have tested our technology by implementing it in microscopes owned by imaging centers on campus at the University of Illinois at Urbana-Champaign, the partner organization of this project. We began commercial exploration by contacting major manufacturers of confocal microscopes and obtained a demo microscope to test our technology with. Further, University of Illinois students participating in the TE401 class were involved and produced a brochure about our technology that was distributed across the UIUC campus to make aware of our technology and seek out potential customers. Furthermore, we applied SOH to vibration imaging in microelectromechanical systems (MEMS) devices.Extensive work has also been performed in regard to using phase imaging for cancer research. Histopathology is a key element in the diagnosis of cancer. Novel methods based on chemical contrast can provide for augmented and automated histopathology based on machine learning. We made a discovery that phase and infrared contrast can be combined to provide a platform for automated histopathology that solves the issues of current infrared technology by (a) improving cost-efficiency and (b) offering higher spatial resolution. To demonstrate this, we built a prototype microscope of this technology and validated it by imaging a breast tissue. First data showed that we are able to resolve the different cell types and disease state of breast tissue sections. Importantly, human interpretation of the data is not required, but it is done in an automated fashion on a computer using statistical analysis.Synthetic optical holography also promises improvement for near-field microscopy. It was demonstrated that synthetic optical holography also allows for near-field imaging at two to three wavelength simultaneously. This capability enables quicker characterization of two-dimensional materials (such as plasmon dispersion mapping in graphene), as well as enables identification of organic material on the nanoscale based on chemical contrast. Until now, repeated scans were required to do so. Results could trigger further research to image at even larger numbers of wavelength simultaneously and so enable more robust material identification. Importantly, the implementation of this modality can be done in software and technology transfer seems favorable. Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far) Our technology is significantly cheaper and produces better quality images than established phase resolving microscopes. These prospects can be expected to help establishing phase imaging in laboratories and thus contribute to the development and promotion of this technology which is still in its emerging phase. Our technology has potential for exploitation and commercialization. To this end, we are working with an imaging center and seeking collaborators make our technology available to users. This is an ongoing effort that will continue after the end of SYNTOH.The most important result of this project is the development of a new technology for infrared imaging that solves a variety of shortcomings of current infrared technology. It removes the need for special IR microscope equipment such as infrared detectors and optics, and replaces these components with an optical microscope which is easy to operate and offers fast imaging. Thus, it could finally pave the way for clinical translation of IR imaging and thereby add value to pathology by (a) reducing cost and time (b) preventing errors of manual tissue inspection (c) enabling diagnostic assistance and (d) enabling prognosis exceeding human capability. While this project only took the first step in development and validation, in our opinion this technique could have far-reaching changes in the way infrared imaging is done. The reduced technical complexity could lead to a wider adoption of infrared imaging. toc-image-schnell.png
