Classical and Quantum Imaging and Metrology Using Far Field Radiation

In this thesis I examine how the statistical properties of radiation limit our ability to perform imaging and metrological procedures. In particular I focus on radiation in the far field zone of the source. The classical and quantum theories of parameter estimation are introduced and subsequently utilised throughout, along with the theory of optical coherence. Classical and quantum imaging protocols are examined with the aid of a resolution criterion and the criterion is shown to reproduce the results of previous works. This method is also extended to previously un-investigated situations and the effect of imperfect measurements is explored. Intensity correlation measurements are investigated in great detail and for the first time a rigorous comparison is made between higher-order intensity correlation measurements of the type introduced by Hanbury Brown and Twiss. The importance of considering covariances in intensity correlation data is demonstrated and I give a full, detailed account of how to include this in the formulation. I also show how the optimal arrangement for an intensity correlation measurement can be found, therefore allowing the best precision in parameter estimation to be achieved. A quantum mechanical description of blackbody radiation is used to examine the state arriving at a detector in the far field. By using the quantum Fisher information an interesting connection is found between the statistical independence of photons in the source plane and the acquisition of information in the far field.