An optical beam delivery device formed of optical fibers that are configured to produce an output exhibiting an intensity distribution profile having non-zero ellipticity includes a first length of fiber through which an incident optical beam having beam characteristics propagates and which has a first refractive index profile (RIP). The first RIP enables, in response to an applied perturbation, modification of the beam characteristics of the optical beam to form an adjusted beam having modified beam characteristics relative to the beam characteristics of the optical beam. A second length of fiber is coupled to the first length of fiber and formed with a set of one or more confinement regions that define a second RIP and confine at least a portion of the adjusted beam to generate, at an output of the second length of fiber, an intensity distribution profile having non-zero ellipticity.