DESC0025057

The changing global nuclear security landscape requires new imaging tools for remote detection applications such as detecting, locating, and characterizing nuclear fuel cycle signatures and facilities. Enhancing signal collection of different optical field signatures such as intensity and wavelength can provide a detailed understanding of objects and activities in a scene. This proposal integrates nanoresonant photodiodes with an electrically modulated liquid crystal as a method for introducing dynamic, controllable, narrow-band wavelength detection. Utilizing wavelength- and subwavelength- sized Mie photo sensor pixels to integrate high resolution spectral and spatial information and liquid crystals as a medium around the sensor this proposal explores the ability to induce large changes in the surrounding mediumĺs index of refraction, thereby stably, reversibly, and incrementally shifting pixel wavelength selectivity using an applied electric field. Phase I is a feasibility study that employs simulation and experimental work to develop a silicon Mie photo sensor design that enables controlled shifts in the spectral power absorption using an applied electric field. The challenges in commercially fabricating nanoresonant sensors incorporating liquid crystals as a surrounding medium will be explored with the goal of developing a viable fabrication process flow. Potential project phases II and III would begin to implement the fabrication process flow, delivering early prototypes of the dynamically controlled photo sensors. This novel imaging system would play an important role in the detection and characterization of global nuclear security threats, cross-cutting functions and foundational capabilities across nonproliferation, counterterrorism, and emergency response mission areas, enabling effective emergency response, advanced safeguards, efficient treaty verification, and other government applications. It also has important commercial remote sensing applications including precision agriculture, security, and land management. Summary for Members of Congress: The changing global nuclear security landscape requires improved remote imaging technologies for detecting, locating, and characterizing nuclear fuel cycle signatures and facilities. This proposal will develop sensors that use resonance effects to couple incident electro-optical radiation to signal production with controllable resonant frequency, enabling fine-tuning of the signal collection for multispectral, snapshot imaging and sensing.