Double-pass copper vapor laser master-oscillator power-amplifier systems

generation of flat-top focused beams for fiber coupling and percussion drilling

David W. Coutts*

*Corresponding author for this work

Research output: Contribution to journalArticle

38 Citations (Scopus)
79 Downloads (Pure)


In this paper, a compact master-oscillator power-amplifier laser system incorporating telescopic beam expansion in a high-gain double-pass amplifier is presented. A miniature (0.5 W) master-oscillator copper vapor laser is used to efficiently extract over 37 W of high-beam-quality (full transverse coherence) output power from a kinetically enhanced nominally 35-W copper vapor laser at 12-kHz pulse repetition frequency. By configuring the oscillator for low coherence output and using a multimode optical fiber between the oscillator and the double-pass amplifier, a high-power (34 W) low-divergence output beam having a well-defined flat-top far-field beam profile was also produced. The flat-top far-field beam profile arises from control of the spatial coherence of a flat-top near-field beam, rather than the usual techniques for producing flattened Gaussian beams from coherent Gaussian beams. Use of the flat-top focused beam for high-speed percussion drilling of high quality 100-μm diameter holes in metals was demonstrated, as well as high-power (34-W average power, 80-kW peak power) damage-free power transmission through 100-μm core diameter step-index optical fibers.

Original languageEnglish
Pages (from-to)1217-1224
Number of pages8
JournalIEEE Journal of Quantum Electronics
Issue number9
Publication statusPublished - Sep 2002
Externally publishedYes


Bibliographical note

Copyright 2002 IEEE. Reprinted from IEEE journal of quantum electronics. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Macquarie University’s products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to By choosing to view this document, you agree to all provisions of the copyright laws protecting it.


  • Gas lasers
  • Laser amplifiers
  • Laser beams
  • Laser materials-processing applications
  • Micromachining
  • Optical fiber coupling
  • Optical pulse amplifiers

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