nLIGHT, Inc.
Optical beam delivery device formed of optical fibers configured for beam divergence or mode coupling control

Abstract:

An optical beam delivery device is formed of optical fibers configured for beam divergence or mode coupling control. An incident optical beam propagates through a first length of fiber, which is coupled to a second length of fiber and has a first refractive index profile (RIP). The first RIP enables, in response to an applied perturbation, modification of the beam characteristics of the incident optical beam to form an adjusted optical beam having modified beam characteristics relative to beam characteristics of the incident optical beam. The second length of fiber is formed with one or more confinement regions defining a second RIP and arranged to confine at least a portion of the adjusted optical beam. The second and first lengths of fiber are tapered in the direction of light beam propagation to control output beam divergence or susceptibility to beam mode coupling in the first length of fiber, respectively.