Fiber laser apparatus, namely, industrial fiber lasers that generate high power laser beams in gain fibers; fiber-coupled laser apparatus, namely, laser diode modules that generate laser beams with semiconductor lasers and couple the laser beams into optical fibers for pumping laser gain media, industrial fiber laser systems comprised of laser equipment for non-medical purposes that use laser diode modules to pump gain fibers, industrial fiber laser systems comprised of laser equipment for non-medical purposes that combine fiber laser beams; fiber laser apparatus with variable optical beam characteristics, namely, industrial fiber lasers that generate high power laser beams with adjustable beam characteristics, including cross-sectional beam shape and intensity profile; fiber-coupled laser apparatus with variable optical beam characteristics namely, laser diode modules that generate laser beams with semiconductor lasers and couple the laser beams into optical fibers for pumping laser gain media and wherein the laser beams in the optical fibers have adjustable beam characteristics, industrial fiber laser systems comprised of laser equipment for non-medical purposes that use laser diode modules to pump gain fibers, industrial fiber laser systems comprised of laser equipment for non-medical purposes that combine fiber laser beams wherein the fiber laser beams have adjustable beam characteristics including cross-sectional beam shape and intensity profile; optical fiber couplers configured to vary beam characteristics of an optical beam propagating in an optical fiber; optical systems comprised of optical fibers and optical beam perturbation systems comprised of laser equipment for non-medical purposes that vary characteristics of a propagating laser beam; optical products for controlling, manipulating, or adjusting optical beam characteristics of fiber laser beams, namely, selectively bendable optical fibers, electroacoustic-optic transducers, electrically controlled devices that vary optical fiber refractive index profile, electrically controlled heaters specially adapted for use with optical fibers, namely, heaters configured to selectively heat optical fibers, piezoelectric transducers, adjustable diffraction gratings being structural parts of optical fibers; optical fiber products for varying beam spatial power distribution, namely, optical fibers with specialized refractive index profiles, optical confinement fibers, optical fiber diffraction gratings being structural parts of optical fibers; optical fiber perturbation devices, namely, optical fiber micro-benders specially adapted for use with optical fibers, optical fiber stretchers, piezo-electric transducers, electrically controlled heaters specially adapted for use with optical fibers, optical fiber coolers specially adapted for use with optical fibers, tubing for use with optical fibers, namely, optical fiber flexible tubing, optical fiber fasteners specially adapted for use with optical fibers, optical fiber clamps specially adapted for use with optical fibers, optical fiber benders specially adapted for use with optical fibers, optical fiber perturbation device electric actuators, optical fiber electro-optic transducers, electroacoustic-optic transducers; apparatus for perturbing optical fibers to vary optical beam characteristics, namely, optical fiber micro-benders specially adapted for use with optical fibers, optical fiber stretchers specially adapted for use with optical fibers, piezo-electric transducers, electrically controlled heaters specially adapted for use with optical fibers, optical fiber coolers specially adapted for use with optical fibers, tubing for use with optical fibers, namely, optical fiber flexible tubing, optical fiber fasteners specially adapted for use with optical fibers, optical fiber clamps specially adapted for use with optical fibers, optical fiber benders specially adapted for use with optical fibers, optical fiber perturbation device electric actuators, optical fiber electro-optic transducers, electroacoustic-optic transducers; fiber laser apparatus having optical fiber splices, namely, laser equipment for non-medical purposes in the nature of splices for optically transmissive fibers that are associated with varying fiber laser output beam characteristics; laser equipment for non-medical purposes, namely, fiber lasers having optical fibers and optical splices associated with variable output beam characteristics