Accession Number : ADA517983


Title :   High-Power Fiber Lasers for Directed-Energy Applications


Descriptive Note : Journal article


Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC PLASMA PHYSICS DIV


Personal Author(s) : Sprangle, P. ; Ting, A. ; Penano, J. ; Fischer, R. ; Hafizi, B.


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA517983


Report Date : 2008


Pagination or Media Count : 12


Abstract : High-power fiber lasers can be incoherently combined to form the basis of a high-energy laser system for directed-energy applications. These applications include tactical directed energy and power beaming. Incoherent combining of fiber lasers has a number of advantages over other laser beam combining methods. The incoherently combined laser system is relatively simple, highly efficient, compact, robust, low-maintenance, and reliable. In this article, we characterize the atmospheric propagation of incoherently combined, high optical quality laser beams and compare them with other types of laser beams and combining methods. For tactical directed-energy applications, we find that the propagation efficiency of incoherently combined high optical quality beams is near the theoretical upper limit for any laser system with the same beam director and total power. We present results of the first atmospheric propagation experiments using incoherently combined, kilowatt-class, single-mode fiber lasers. These NRL field experiments combined four fiber lasers using a beam director consisting of individually controlled steering mirrors. The transmitted continuous-wave power was 3 kW at a range of 1.2 km with a demonstrated propagation efficiency of tilde 90% in moderate atmospheric turbulence. The experimental results are found to be in good agreement with simulations and theory.


Descriptors :   *FIBER OPTICS , *HIGH POWER , *LASERS , OPTICAL PROPERTIES , OPTICS , FIBERS , STEERING , ENERGY , CONTINUOUS WAVES , FIELD TESTS , ATMOSPHERIC PHYSICS , TURBULENCE , ATMOSPHERIC MOTION , LASER BEAMS , HIGH ENERGY , WAVE PROPAGATION , LIMITATIONS , POWER , TACTICAL WARFARE , BEAMS(RADIATION) , DIRECTIONAL , PROPAGATION , CONTROL , MIRRORS , EFFICIENCY


Subject Categories : ELECTRICAL AND ELECTRONIC EQUIPMENT
      LASERS AND MASERS
      DEFENSE SYSTEMS
      DIRECTED ENERGY WEAPONS
      FIBER OPTICS AND INTEGRATED OPTICS
      ATMOSPHERIC PHYSICS


Distribution Statement : APPROVED FOR PUBLIC RELEASE