The University of California, Los Angeles (UCLA) has made a groundbreaking achievement in the realm of optical imaging technology. A new all-optical complex field imager has been developed, marking a significant advancement in the field. This innovative device has the capability to capture both amplitude and phase information of optical fields without the need for digital processing. The implications of this technology are far-reaching, with potential applications in biomedical imaging, security, sensing, and material science.
Traditional optical imaging techniques rely on intensity-based sensors that can only capture the amplitude of light, neglecting the crucial phase information. Phase information is vital as it provides insights into structural properties such as absorption and refractive index distributions, essential for detailed sample analysis. Current methods for capturing phase information involve complex interferometric or holographic systems supported by iterative phase retrieval algorithms, leading to increased hardware complexity and computational demand.
Led by Professor Aydogan Ozcan, a team at UCLA has developed a novel complex field imager that overcomes these limitations. This innovative device utilizes a series of deep learning-optimized diffractive surfaces to modulate incoming complex fields. These surfaces create two independent imaging channels that convert the amplitude and phase of the input fields into intensity distributions on the sensor plane. By doing so, the need for digital reconstruction algorithms is eliminated, drastically simplifying the imaging process.
The new complex field imager comprises spatially engineered diffractive surfaces arranged to carry out amplitude-to-amplitude and phase-to-intensity transformations. These transformations enable the device to directly measure the amplitude and phase profiles of input complex fields. Despite its complexity, the imager has a compact optical design that spans approximately 100 wavelengths axially, making it highly integrable into existing optical systems. The researchers validated their designs through 3D-printed prototypes operating in the terahertz spectrum, showcasing a high degree of accuracy in the output amplitude and phase channel images closely resembling numerical simulations.
The development of the all-optical complex field imager has opened up a vast array of potential applications. In the biomedical field, this technology can be utilized for real-time, non-invasive imaging of tissues and cells, offering critical insights during medical procedures. Its compact and efficient design makes it well-suited for integration into endoscopic devices and miniature microscopes, potentially advancing point-of-care diagnostics and intraoperative imaging. Furthermore, in environmental monitoring, the imager can aid in the development of portable lab-on-a-chip sensors for rapid detection of microorganisms and pollutants, streamlining the process of environmental assessment.
The complex field imager also holds promise for industrial applications, where it can be used for rapid material inspection. Its ability to capture detailed structural information without the need for bulky equipment or extensive computational resources makes it a valuable asset in quality control and material analysis. The compact and efficient design of the imager enhances its usability in various industries, offering a new dimension to the way materials are inspected and analyzed.
The development of the all-optical complex field imager represents a significant leap forward in the realm of optical imaging technology. By facilitating the direct capture of amplitude and phase information without digital processing, this technology simplifies the imaging process and opens up new possibilities for applications across different fields. As researchers continue to refine and expand upon their designs, the impact of this innovation is expected to grow, providing fresh opportunities for scientific research and practical implementations across diverse sectors.