Correlation Imaging Using Scattered Waves and Its Applications

Abstract

Scattering mediums present significant challenges in the realm of imaging, complicating the mapping between object and image planes and often degrading the performance of conventional imaging techniques. However, within this complexity lies the potential of novel applications. One notable example is exploring the second-order correlation of scattered light, initiated by the landmark Hanbury Brown and Twiss experiment in quantum optics, which yields profound insights into quantum interference and imaging in entangled photon systems. Interestingly, the joint-detection probability of two detectors markedly amplifies upon simultaneous “clicks,” contrasting with delayed events beyond the coherence time of scattered light. While it is classically explainable by intensity fluctuation correlation, quantum mechanically, this phenomenon emerges from the constructive interference of indistinguishable two-photon detection amplitudes. In contemporary quantum physics research, the Hanbury-Brown and Twiss interferometry has become essential for bunching and anti-bunching phenomena of the photon, electron, and atom. Moreover, the distorted wavefront induced by scattering mediums shows superior performance over the flat wavefront of conventional imaging systems, particularly in environments within scattering media or atmospheric turbulence. Hence, a comprehensive investigation into correlation imaging with scattered light is paramount, offering a gateway to innovative applications in this growing field. This thesis delves into the advantages of correlation imaging with scattered fields within this framework. Interestingly, our studies showcase the coherent two-photon LIDAR utilizing scattered light beyond the coherence length, leveraging the counter-intuitive nature of second-order or two-photon interference. We also show that our coherent two-photon LIDAR with scattered light is robust through air turbulence, unlike the conventional coherent LIDAR system. We conduct a thorough investigation into the theory of second-order interference and our LIDAR system. Additionally, we demonstrate the correlation imaging systems for acoustic waves and microwaves. Finally, we explore the computational advantages of correlation measurement systems using quantum light within scattering media. From a practical standpoint, we hope that our research paved the way for novel applications, such as remote sensing. By bridging theoretical insights with experimental validation, this thesis contributes to the evolving landscape of correlation imaging with scattered waves, leading the way for advancements in the field.