An optical fiber comprising: (i) a chlorine doped silica based core comprising a core alpha ()>10, and maximum refractive index delta .sub.1max % and Cl concentration >1 wt %; (ii) a cladding surrounding the core, the cladding comprising: (a) an inner cladding region adjacent to and in contact with the core and having a refractive index delta .sub.2 and a minimum refractive index delta .sub.2min such that .sub.2min<.sub.1max, the inner cladding region comprising fluorine doped silica and the refractive index delta .sub.2 with region that decreases with radial position, and (b) an outer cladding region surrounding the inner cladding region and having refractive index delta .sub.3, such that .sub.2min<.sub.3. The fiber has mode field diameter MFD at 1310 nm of 9 microns, a cable cutoff of 1260 nm, zero dispersion wavelength of 1300 nmzero dispersion wavelength 1324 nm and bend loss at 1550 nm for a 20 mm mandrel of less than 0.5 dB/turn.

An optical beam delivery device includes: a first length of fiber having a first refractive index profile (RIP) to enable modification of one or more beam characteristics of an optical beam having a first beam shape; an a second length of fiber having at least one beam-shaping confinement region and situated to receive the optical beam from the first length of fiber, wherein the at least one beam shape-modifying confinement region has a quadrilateral cross-section.

A loop memory cell (LMC) includes a minimum of one optical loop coupled by a minimum of one input armlet and on output armlet. The input armlet(s) can couple only in one direction, from the input armlet(s) into the optical loop, and not back. The output armlet(s) can couple or not, according to the refractive index changer, from the optical loop into the output armlet(s). The LMC is configured to collect the input data and store the date in the optical loop until needed. Changing the refractive index the LMC can act as a memory cell or modulator. The LMC overcomes the energy loss of conventional techniques, allowing the creation of variety of building blocks and complex processing blocks for different applications and algorithms. The LMC has increased information storing efficiency, increased data processing speeds, and can modulate data thereby reducing processing complexity and increasing speeds.

An optical power control system includes a laser source to provide an optical beam, a variable beam characteristics (VBC) fiber, and a controller operatively coupled to the VBC fiber and configured to control, in response to information indicating change in optical power of the optical beam, different states of perturbation so as to control optical power density.

An optical beam delivery device is configured to generate, from an optical beam, selectable intensity profiles. The device has a first length of fiber having a first refractive index profile (RIP), and a second length of fiber having second RIP that is different from the first RIP. The second length of fiber includes coaxial confinement regions arranged to confine at least a portion of an adjusted optical beam. The confined portion corresponds to an intensity distribution of different intensity distributions. The intensity distribution is established by a corresponding state of different states of perturbation that is applied to the device such that the confined portion is configured to provide, at an output of the second length of fiber, a selected intensity profile of the selectable intensity profiles.

Fiber bending mechanisms vary beam characteristics by deflecting or bending one or more fibers, by urging portions of one or more fibers toward a fiber shaping surface having a selectable curvature, or by selecting a fiber length that is to be urged toward the fiber shaping surface. In some examples, a fiber is secured to a flexible plate to conform to a variable curvature of the flexible plate. In other examples, a variable length of a fiber is pulled or pushed toward a fiber shaping surface, and the length of the fiber or a curvature of the flexible plate provide modification of fiber beam characteristics.

A method of materials processing using an optical beam includes: launching the optical beam into a first length of fiber having a first refractive-index profile (RIP); coupling the optical beam from the first length of fiber into a second length of fiber having a second RIP; modifying one or more beam characteristics of the optical beam in the first length of fiber, in the second length of fiber, or in the first and second lengths of fiber; and/or generating an output beam, having the modified one or more beam characteristics of the optical beam, from the second length of fiber. The first RIP can be the same as or differ from the second RIP. The modifying of the one or more beam characteristics can include changing the one or more beam characteristics from a first state to a second state. The first state can differ from the second state.

Disclosed herein are methods, apparatus, and systems for providing an optical beam delivery system, comprising an optical fiber including a first length of fiber comprising a first RIP formed to enable, at least in part, modification of one or more beam characteristics of an optical beam by a perturbation assembly arranged to modify the one or more beam characteristics, the perturbation assembly coupled to the first length of fiber or integral with the first length of fiber, or a combination thereof and a second length of fiber coupled to the first length of fiber and having a second RIP formed to preserve at least a portion of the one or more beam characteristics of the optical beam modified by the perturbation assembly within one or more first confinement regions. The optical beam delivery system may include an optical system coupled to the second length of fiber including one or more free-space optics configured to receive and transmit an optical beam comprising the modified one or more beam characteristics.

Systems and methods for modifying an optical beam and adjusting one or more beam characteristics of an optical beam are provided. The system may include a first length of fiber operably coupled with an optical beam source and configured to receive an optical beam therefrom. The system may also include a perturbation device operably coupled with the first length of fiber and configured to modify the optical beam traversing therethrough, and a second length of fiber operably coupled with the first length of fiber and configured to receive the modified optical beam therefrom. The system may further include a beam shaping assembly configured to receive the modified optical beam from the second length of fiber, adjust one or more beam characteristics of the modified optical beam, and direct the adjusted optical beam to a downstream process.

Additive manufacturing systems and methods for fabricating an article are provided. The additive manufacturing system may include a substrate and a layering device configured to fabricate a first layer of the article on the substrate. The layering device may include an optical beam source configured to generate an optical beam and a variable beam characteristics (VBC) fiber operably coupled with the optical beam source and configured to modify one or more beam characteristics, such as a wavelength, of the optical beam.