Spatiotemporal wavevector dynamics of transverse mode-locked beams

The phase-locking of transverse higher-order resonator modes results in a beam with rapidly oscillating spatial intensity profile. To complete the description of such transverse mode-locked (TML) beams, their spatiotemporal phase dynamics are explored in this work. The analysis of the phase terms of TML beams reveals oscillating wavevectors, which are experimentally verified by exploiting the mode-matching requirement of a single-mode fiber. The wavevector oscillation is further quantified by exploring its dependence on beam size. The findings have to be considered in potential future applications of TML beams in phase-sensitive processes.