SUMMARY

Holography is an optical diagnostic capable of imaging three-dimensional multi-phase and particle-laden flows via numerical refocusing of diffraction patterns. However, digital in-line holography is limited in extreme environments due to phase distortions caused by index of refraction gradients. Furthermore, measurements in these extreme systems often require long stand-off distances and high magnification. To overcome these challenges, numerical phase-cancellation holography using polarization and off-axis holography configurations can be used. This allows for phase delays to be numerically corrected in post-processing, effectively removing phase distortions. Furthermore, relay imaging methods are used to achieve high magnification holography with long standoff distances. Distortion correction is added to these methods by performing numerical reference phase front correction. Furthermore, complimentary diagnostics such as imaging pyrometry and imaging focused laser differential interferometry will be paired with the holography techniques to provide joint temperature and phase fluctuation measurements. To prove the capability of these diagnostics, particles and droplets from aluminized propellants, pyrotechnics and supersonic sprays are measured. Moving forward, these diagnostics can be used to make measurements in combustor injection systems, supersonic atomization, and other extreme droplet and particle systems.