The vital gases carry through the hemoglobin; hence, the detection and analysis of hemoglobin concentration are crucial in the physiology processes. In this context, we introduce a biosensor based on a one-dimensional photonic crystal with a defect layer for oxygen sensing in hemoglobin. In this innovative approach, hemoglobin is the defect layer and its refractive index changes with oxygen dissolution. The variation of the refractive index leads to a shift in the transmission spectrum, which can be utilized to distinguish between oxygenated and deoxygenated hemoglobin. The theoretical investigation of transmission spectra using the transfer matrix method reveals that both hemoglobin states can be effectively distinguished. The proposed sensor exhibits remarkable sensitivity, particularly with the optimum structure featuring a defect layer thickness of 12 μm, seven layers, and an incident angle (θ) of 81 deg, providing a sensitivity of 1510.5 nm/RIU. These findings underscore the high-performance potential of our sensor in the region of oxygen sensing in biology, particularly in medical applications.
An optically addressable liquid crystal spatial light modulator (SLM) is used for dynamic laser beam shaping used in a unique, fast metal additive manufacturing process (3D printing) [1]. We address challenges of using our SLM exposed continuously to high power kW-MW lasers. Control of liquid crystals is coupled to the optical-response of the photoconducting insulators that affects contrast, switching speed, and laser power handling. We compare liquid crystal materials laser damage rationalized based on their thermal properties, and highlight device-level stresses via computational modeling. Key areas of liquid crystals and semiconductor properties are presented that impact optically addressed SLM for power switching applications.
[1] https://www.seurat.com/area-printing
An optically addressed light valve is described for high-speed laser beam shaping used in rapid metal additive manufacturing [1]. The resulting Area Printing™ delivers shaped high-power pulses to a metal powder bed that locally sinters and melts to consolidate into a fully dense metal part. This technology and device enable scaling, cheaper additive manufacturing with high spatial resolution and greater efficiency with minimal spatter defects. We address here the unique optoelectronic properties and challenges related to optically addressed photoconducting insulator that control the switching dynamics under high intensity laser irradiation. Further description is presented of the device-level thermomechanical analysis from parasitic absorption of the laser at kW to MW power levels.
[1] https://www.seurat.com/area-printing
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