FIG. 2.

Effect of shot noise on time-reversal fidelity. (a) The intensity distribution of the phase conjugate beam was directly visualized by the CCD sensor. Left and middle: With the phase conjugate beams generated at ${\overline{n}}_s/M$ of ~2000 and ~0.004. Right: With an unshaped incident beam (i.e., plane pattern on SLM). (b) Experimental and theoretical enhancement versus the total number of input photons ${\overline{n}}_s$. The solid curve and dotted curve, respectively, represent the theoretical and experimental enhancement.