Optical interferometry in the presence of large phase diffusion
  Phase diffusion represents a crucial obstacle towards the implementation of high precision interferometric measurements and phase shift based communication channels. Here we present a nearly optimal interferometric scheme based on homodyne detection and coherent signals for the detection of a phase shift in the presence of large phase diffusion. In our scheme the ultimate bound to interferometric sensitivity is achieved already for a small number of measurements, of the order of hundreds, without using nonclassical light. 
Marco G. Genoni, Stefano Olivares, Davide Brivio, Simone Cialdi,   Daniele Cipriani, Alberto Santamato, Stefano Vezzoli, and...
quant-ph