摘要： Optical ?ber communication serves a signi?cant role in recent communication. Investigated in the work is a coupled fourth-order nonlinear Schr?dinger system for the ultrashort optical pulses in a two-mode optical ?ber. For the complex envelopes of two ?eld polarization components, we work out the Darboux transformation and higher-order vector rogue-wave solutions. The second-order vector rogue waves with the triangle structure, each component of which is composed of three four-petaled rogue waves, are shown. With the strength of the higher-order linear and nonlinear effects increasing, width of the triangle structure along the distance axis decreases, while width of the triangle structure along the time axis increases. We obtain the second-order vector rogue waves with the merged structure and the third-order vector rogue waves with the triangle and pentagon structures. We expect that our results could be helpful in studying the rogue-wave phenomena in the nonlinear optics.