Abstract

The application of an off-axis negative-branch unstable resonator to an active medium of rectangular geometry is examined. The presented unstable resonator consists of spherical mirrors and a scraper mirror. The adaptation to the rectangular cross section is performed by the scraper, which takes two different shapes. One shape resembles a rectangular bracket “[” and the other resembles the letter “L.” The [ and L configurations correspond to a shift of the optical axis away from the center of the cross section, toward one of the edges or toward one of the corners, respectively. Both scraper setups are examined numerically and experimentally. Experiments are performed with a multikilowatt class chem- ical oxygen iodine laser. The active medium is characterized by a low amplification coefficient. Measured results of the intensity distribution in the far field and of the phase distribution in the near field are shown for both resonator configurations. Using the same resonator magnification, the setup with the L-shaped scraper has a lower output coupling and, therefore, a higher output power and a slightly higher beam divergence. The L-shaped scraper configuration is able to cover the gain medium completely.

© 2010 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. A. E. Siegman, “Unstable optical resonators,” Appl. Opt. 13, 353–367 (1974).
    [CrossRef] [PubMed]
  2. Y. Jin, B. Yang, F. Sang, D. Zhou, L. Duo, and Q. Zhuang, “Experimental investigation of an unstable ring resonator with 90-deg beam rotation for a chemical oxygen iodine laser,” Appl. Opt. 38, 3249–3252 (1999).
    [CrossRef]
  3. T. Hall, “Numerical studies on hybrid resonators for a medium sized COIL,” Opt. Eng. 44, 114201 (2005).
    [CrossRef]
  4. J. Handke, W. O. Schall, T. Hall, F. Duschek, and K. M. Grünewald, “Chemical oxygen-iodine laser power generation with an off-axis hybrid resonator,” Appl. Opt. 45, 3831–3838 (2006).
    [CrossRef] [PubMed]
  5. C. Pargmann, T. Hall, F. Duschek, K. M. Grünewald, and J. Handke, “Hybrid resonator in a double-pass configuration for a chemical oxygen iodine laser,” Appl. Opt. 47, 6644–6649(2008).
    [CrossRef] [PubMed]
  6. T. Hall, F. Duschek, K. M. Grünewald, and J. Handke, “Modified negative branch confocal unstable resonator,” Appl. Opt. 45, 8777–8780 (2006).
    [CrossRef] [PubMed]
  7. C. Pargmann, T. Hall, F. Duschek, K. M. Grünewald, and J. Handke, “COIL emission of a modified negative-branch confocal unstable resonator,” Appl. Opt. 46, 7751–7756 (2007).
    [CrossRef] [PubMed]
  8. N. Hodgson and T. Haase, “Beam parameters, mode structure and diffraction losses of slab lasers with unstable resonators,” Opt. Quantum Electron. 24, S903–S926 (1992).
    [CrossRef]
  9. J. Handke, K. Grünewald, and W. O. Schall, “Power extraction investigations for a 10kW-class supersonic COIL,” Proc. SPIE 3574, 309–314 (1998).
    [CrossRef]
  10. K. M. Grünewald, J. Handke, and F. Duschek, “Small signal gain and temperature profiles in supersonic COIL,” Proc. SPIE 4184, 75–78 (2001).
    [CrossRef]
  11. J. W. Goodman, Introduction to Fourier Optics (McGraw-Hill, 1968).
  12. A. G. Fox and T. Li, “Resonant modes in a maser interferometer,” Bell Syst. Tech. J. 40, 453–488 (1961).
  13. M. Born and E. Wolf, Principles of Optics (Cambridge University, 1999).

2008

2007

2006

2005

T. Hall, “Numerical studies on hybrid resonators for a medium sized COIL,” Opt. Eng. 44, 114201 (2005).
[CrossRef]

2001

K. M. Grünewald, J. Handke, and F. Duschek, “Small signal gain and temperature profiles in supersonic COIL,” Proc. SPIE 4184, 75–78 (2001).
[CrossRef]

1999

1998

J. Handke, K. Grünewald, and W. O. Schall, “Power extraction investigations for a 10kW-class supersonic COIL,” Proc. SPIE 3574, 309–314 (1998).
[CrossRef]

1992

N. Hodgson and T. Haase, “Beam parameters, mode structure and diffraction losses of slab lasers with unstable resonators,” Opt. Quantum Electron. 24, S903–S926 (1992).
[CrossRef]

1974

1961

A. G. Fox and T. Li, “Resonant modes in a maser interferometer,” Bell Syst. Tech. J. 40, 453–488 (1961).

Born, M.

M. Born and E. Wolf, Principles of Optics (Cambridge University, 1999).

Duo, L.

Duschek, F.

Fox, A. G.

A. G. Fox and T. Li, “Resonant modes in a maser interferometer,” Bell Syst. Tech. J. 40, 453–488 (1961).

Goodman, J. W.

J. W. Goodman, Introduction to Fourier Optics (McGraw-Hill, 1968).

Grünewald, K.

J. Handke, K. Grünewald, and W. O. Schall, “Power extraction investigations for a 10kW-class supersonic COIL,” Proc. SPIE 3574, 309–314 (1998).
[CrossRef]

Grünewald, K. M.

Haase, T.

N. Hodgson and T. Haase, “Beam parameters, mode structure and diffraction losses of slab lasers with unstable resonators,” Opt. Quantum Electron. 24, S903–S926 (1992).
[CrossRef]

Hall, T.

Handke, J.

Hodgson, N.

N. Hodgson and T. Haase, “Beam parameters, mode structure and diffraction losses of slab lasers with unstable resonators,” Opt. Quantum Electron. 24, S903–S926 (1992).
[CrossRef]

Jin, Y.

Li, T.

A. G. Fox and T. Li, “Resonant modes in a maser interferometer,” Bell Syst. Tech. J. 40, 453–488 (1961).

Pargmann, C.

Sang, F.

Schall, W. O.

J. Handke, W. O. Schall, T. Hall, F. Duschek, and K. M. Grünewald, “Chemical oxygen-iodine laser power generation with an off-axis hybrid resonator,” Appl. Opt. 45, 3831–3838 (2006).
[CrossRef] [PubMed]

J. Handke, K. Grünewald, and W. O. Schall, “Power extraction investigations for a 10kW-class supersonic COIL,” Proc. SPIE 3574, 309–314 (1998).
[CrossRef]

Siegman, A. E.

Wolf, E.

M. Born and E. Wolf, Principles of Optics (Cambridge University, 1999).

Yang, B.

Zhou, D.

Zhuang, Q.

Appl. Opt.

Bell Syst. Tech. J.

A. G. Fox and T. Li, “Resonant modes in a maser interferometer,” Bell Syst. Tech. J. 40, 453–488 (1961).

Opt. Eng.

T. Hall, “Numerical studies on hybrid resonators for a medium sized COIL,” Opt. Eng. 44, 114201 (2005).
[CrossRef]

Opt. Quantum Electron.

N. Hodgson and T. Haase, “Beam parameters, mode structure and diffraction losses of slab lasers with unstable resonators,” Opt. Quantum Electron. 24, S903–S926 (1992).
[CrossRef]

Proc. SPIE

J. Handke, K. Grünewald, and W. O. Schall, “Power extraction investigations for a 10kW-class supersonic COIL,” Proc. SPIE 3574, 309–314 (1998).
[CrossRef]

K. M. Grünewald, J. Handke, and F. Duschek, “Small signal gain and temperature profiles in supersonic COIL,” Proc. SPIE 4184, 75–78 (2001).
[CrossRef]

Other

J. W. Goodman, Introduction to Fourier Optics (McGraw-Hill, 1968).

M. Born and E. Wolf, Principles of Optics (Cambridge University, 1999).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (6)

Fig. 1
Fig. 1

MNBUR in rectangular geometry with a [-shaped scraper. The gain medium (not shown here) is placed between the back mirror and the scraper. The optical axis is horizontally shifted apart from the symmetry center and the radiation field does not cover the complete cross section of the gain medium.

Fig. 2
Fig. 2

Upper graph: experimental setup of the MNBUR with an L-shaped scraper. Lower graph: view onto the output mirror, showing the optimum position of the scraper and the optical axis. M is the resonator magnification and X and Y denote the width and the height of the gain medium, respectively.

Fig. 3
Fig. 3

Measured and calculated intensity distributions of the far fields obtained with the [-shaped scraper (upper pictures) and the L-shaped scraper setup (lower pictures).

Fig. 4
Fig. 4

Phase measurement of the near field of the MNBUR with an L-shaped scraper. One hundred pixels correspond to 25.9 mm in the plane of the near field.

Fig. 5
Fig. 5

Far-field intensity distributions obtained from the L-setup at different resonator lengths.

Fig. 6
Fig. 6

Calculated output coupling and divergence of the main bulk of the far field (defined by the first minimum) of the MNBUR with the L-shaped scraper in dependence on the magnification M. The cross section has a rectangular shape and is 25 mm high and 34 mm wide.

Metrics