Development of an ultra-broadband microscope - optical microscopy is a cornerstone of biomedical research, enabling detailed visualization of biological structures and processes

The National Institute of General Medical Sciences awarded the University of Arizona $1.835 million on May 11, 2026, under the Biomedical Research and Research Training program (CFDA 93.859) to develop an ultra-broadband microscope based on an innovative obscuration-free, off-axis freeform reflective optical architecture.

The project addresses fundamental limitations of conventional optical microscopy by designing and optimizing a compact, high-performance reflective microscope capable of diffraction-limited imaging across an ultra-broadband spectral range spanning the ultraviolet through infrared wavelengths. The system eliminates chromatic aberrations and optical dispersion inherent to traditional refractive designs while avoiding the central obscuration that reduces contrast and efficiency in existing reflective systems. Project objectives include design and optimization of the off-axis reflective microscope, prototype fabrication and assembly using advanced diamond-turning techniques, and performance validation through experimental testing across UV, visible, and infrared spectra to benchmark the prototype against state-of-the-art commercial systems.

Work is performed in Tucson, Arizona, with a period of performance through April 30, 2030. The University of Arizona received the award as the operating entity of the Arizona Board of Regents.

However, traditional refractive microscopes are inherently limited by chromatic aberrations, group delay dispersion, and narrow spectral ranges, while existing reflective designs suffer from central obscuration, reducing contrast and efficiency. These limitations restrict the ability to perform high-resolution, broadband, and multimodal imaging, hindering advancements in biomedical research. To address these challenges, we propose the development of an ultra-broadband microscope based on an innovative obscuration-free, off-axis freeform reflective optical architecture. This system is designed to achieve diffraction-limited performance across an ultra-broadband spectral range - from the ultraviolet (UV) to the infrared (IR) - while eliminating chromatic aberrations and minimizing optical dispersion. By leveraging freeform optics and an unobscured reflective design, this technology will provide superior contrast, higher optical efficiency, and enhanced imaging capabilities beyond the limitations of conventional refractive or reflective microscopes. A key innovation of this project lies in the development of off-axis freeform reflective configurations and novel optomechanical integration strategies to create a compact, ultra-broadband-compatible microscope. This project will focus on three key objectives: (1) design and optimization of a compact, high- performance off-axis reflective microscope with diffraction-limited imaging across a wide spectral range. (2) prototype fabrication and assembly, advancing high-precision diamond-turning techniques to ensure superior optical quality and robust system integration. (3) performance validation through rigorous experimental testing across UV, visible, and infrared spectra, benchmarking the prototype against state-of-the- art commercial refractive and reflective microscopes. The anticipated outcome is a transformative microscope platform that enables high-contrast, ultra- broadband imaging with an unprecedented working spectrum. This technology will establish a new paradigm for high-performance optical microscopy, unlocking new opportunities in biomedical research and expanding imaging capabilities across multiple disciplines. This proposal directly aligns with the objectives of nigms nofo (PAR-25-203) by advancing a demonstrated proof-of-concept ultra-broadband microscope into a fully functional prototype with broad applicability in biomedical and biological sciences research. By overcoming fundamental optical constraints, this microscope has the potential to transform biomedical imaging and biological research, facilitating new discoveries and expanding the frontiers of optical microscopy.