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Title: Designing a fiber-optic beam delivery system

Conference ·
OSTI ID:451203
 [1]; ;  [2]
  1. LightPath Technologies, Inc., Albuquerque, NM (United States)
  2. Argonne National Lab., IL (United States); and others

One of the advantages offered by visible and NIR lasers over CO and CO{sub 2} lasers is that they can be delivered through optical fibers. Fiber-optic beam delivery is ideal when the beam must be delivered along a complex path or processing requires complicated manipulation of the beam delivery optics. Harnessing the power of a high-power laser requires that knowledgeable and prudent choices be made when selecting the laser and its beam delivery system. The purpose of this paper is to discuss a variety of issues important when designing a beam delivery system-data obtained with high power Nd:YAG lasers will be used as illustrative examples. (1) Multimode optical fibers are used for high-power applications. The fiber imposes, to varying degrees, a structure on the beam that is different from the laser output. Fibers degrade the beam quality, although the degree of degradation is dependent on the fiber length, diameter and type. Smaller fibers tend to produce less degradation to beam quality, but the minimum usable fiber size is limited by the quality of the laser beam, focusing optic and the numerical aperture of the fiber. (2) The performance of the beam delivery system is ultimately determined by the quality of the optics. Therefore, well-corrected optics are required to realize the best possible performance. Tests with both homogeneous and GRADIUM{trademark} lenses provide insights into evaluating the benefits offered by improvements in the output optics from gradient-index, aspheric and multi-element lens systems. Additionally, these tests illustrate the origins of variable focused spot size and position with increasing laser power. (3) The physical hardware used in the beam delivery system will have several characteristics which enhance its functionality and ease of use, in addition to facilitating the use of advanced diagnostics and monitoring techniques.

Research Organization:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Organization:
USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States)
DOE Contract Number:
W-31109-ENG-38
OSTI ID:
451203
Report Number(s):
ANL/TD/CP-90563; CONF-970231-9; ON: DE97003217; TRN: 97:001940
Resource Relation:
Conference: SPIE international symposium, San Jose, CA (United States), 8-14 Feb 1997; Other Information: PBD: 1997
Country of Publication:
United States
Language:
English