Engineered Micro-Spheres For Optical Filtering

As infrared (IR) imaging technologies improve for the commercial market, optical filters complementing this technology are critical to aid in the insertion and benefit of thermal imaging across markets of industry and manufacturing. Thermal imaging, specific to shortwave infrared (SWIR) through longwave infrared (LWIR) provides the means for an observer to collect thermal information from a scene, whether being temperature gradients or spectral signatures of materials. This is beneficial to applications such as chem/bio sensing, where the identification of a chemical species being present or emitted could compromise personnel or the environment. Due to the abundant amount of information within an environment, the difficulty lies within the observer's ability to extract the information. The use of optical filters paired with thermal imaging provides the means to interrogate a scene by looking at unique infrared signatures. The more efficient the optical filter can either transmit the wavelengths of interest, or suppress other wavelengths increases the finesse of the imaging system. Such optical filters can be fabricated in the form of micro-spheres, which can be dispersed into a scene, where the optical filter's intimate interaction with the scene can supply information to the observer, specific to material properties and temperature. To this extent, Lumilant has made great progress in the design and fabrication of such micro-sphere optical filters. By engineering the optical filter's structure, different optical responses can be tuned to their individual application.