Enhancing the Accuracy of Digital Holography Based Mode Decomposition Method

The mode decomposition method has already proven its usefulness for a wide range of applications. However, there is still a need and potential for improvement when using it in various multimode fiber systems. This work deals with investigating the factors that reduce the accuracy of decomposition and ways to overcome their negative impact. It is shown that the accuracy of the method doubles by adding adaptive exposure, automatic determination of the background signal level, and the weight coefficient of the fundamental mode when measuring relative phases. A combined method of phase correlation filter and matrix-oriented mode decomposition is also conceptually demonstrated allowing the amplitudes and phases of beam modes to be recovered in a single measurement.