Compact optical sensing systems

Optoelectronic devices and techniques are major enablers of compact sensing systems for a wide range of applications that address medical, industrial, civil, defense, and consumer needs. Our vision is to miniaturize devices and systems while enhancing functionality and accessibility. Many challenges confront this endeavor, for example, the size and cost of existing components, need for continuous detection, low light intensities that result from small sensing volume and weak light-target interaction, and detection in complex fluids. Our general strategy is to identify the specific information required for the application, incorporate signal processing (electronics & software) to reduce complexity and cost of the optoelectronic subsystems, improve signal-to-noise discrimination, and integrate all components. Two technologies will be described to illustrate our approach. The first is a compact, low-cost wavelength monitor. The innovation will be illustrated with two examples: (1) precise measurement of the wavelength of individual laser pulses, for applications such as LIDAR, and (2) an optically-based monitoring system prototype targeting batteries for electric vehicles. The system will combine fiber optic sensors embedded inside lithium-ion battery cells with the wavelength-shift detector and intelligent algorithms to measure parameters indicative of cell state and enable responsive real-time performance management. The second technology is a miniaturized opto-fluidic system for on-the-flow analyte characterization. The enabling innovation is termed “spatially modulated emission” and uses signal processing (via electronics & software) to reduce complexity and cost of the optical detection subsystem while maintaining high performance. The technique will be illustrated with CD4% counting in whole blood and pathogen detection in water.