We investigate the beam emerging from a 3m-long passive large mode area multi-core fiber (MCF) at two different wavelengths to demonstrate the analysis of differently complex mode mixtures. Our method uses a computer-generated hologram (CGH) to modally decompose the beam exiting the fiber end facet. At 1064 nm the MCF is measured to be single-mode whereas at 633nm ten modes are guided. The excitation of distinct mode mixtures at 633nm is done by changing the input coupling situation enabled by a nano-positioning device. Furthermore it is demonstrated how bending of the fiber alters the modal spectrum.© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.