Ultra-short Pulsed Off-axis Digital Holography for 3D imaging of Aerosol Evolution

This is a proposal to develop a unique, Ultrashort Pulsed Off-axis Digital Holography (USPODH) system, enabling the high frequency imaging of detailed 3D structures within aerosol fields under harsh thermodynamic conditions and high optical depths where ordinary imaging is essentially useless. Many powerful imaging methods have failed to provide this capability because noise from multiple scattering buries the signal needed to acquire a useful image. The proposed innovation takes advantage of ultrashort pulse lasers for digital holography in an off-axis configuration to limit the amount of optical noise sufficiently to enable high resolution, 3D imaging that is necessary to study aerosol evolution and validate numerical computations. The new product provides a detailed, instantaneous look at the structure and position of all of the aerosols in a large 3D sample volume. Moreover, the system will be capable of recording dynamic information at high frequency. In the Phase I program, we propose to modify the design of our current USPODH system for imaging at harsh thermodynamic conditions and high speed (100 kHz) tracking of aerosol evolution events. We will conduct new experiments for imaging of aerosols at harsh conditions and evaluate the results in comparison with CFD simulations.