Abstract

Pulse-timing effects in the far field of a passively Q-switched microchip laser that are caused by the changing cavity mode during pulse emission are described. Measurements are performed on a passively Q-switched Nd:YAG laser that produces 3-ns pulses, and delays in pulse arrival times of up to 270 ps are observed between the center and the off-axis position. The measured data agree well with a simple analytical model. Pulse delays of this order are important, for instance, in high-precision range-finding applications.

© 2001 Optical Society of America

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References

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  1. B. Braun, F. X. Kärtner, G. Zhang, M. Moser, and U. Keller, Opt. Lett. 22, 381 (1997).
    [CrossRef] [PubMed]
  2. J. J. Zayhowski and C. Dill, Opt. Lett. 19, 1427 (1994).
    [CrossRef] [PubMed]
  3. J. J. Zayhowski, Rev. Laser Eng. 26, 841 (1998).
    [CrossRef]
  4. A. Caprara and G. C. Reali, Opt. Quantum Electron. 24, 1001 (1992).
    [CrossRef]
  5. J. J. Zayhowski and C. Dill, Opt. Lett. 19, 1427 (1994).
    [CrossRef] [PubMed]
  6. K. A. Ameur, Appl. Opt. 36, 7809 (1997).
    [CrossRef]
  7. A. E. Siegman, Lasers (University Science, Mill Valley, Calif., 1986), p. 786.

1998 (1)

J. J. Zayhowski, Rev. Laser Eng. 26, 841 (1998).
[CrossRef]

1997 (2)

1994 (2)

1992 (1)

A. Caprara and G. C. Reali, Opt. Quantum Electron. 24, 1001 (1992).
[CrossRef]

Appl. Opt. (1)

Opt. Lett. (3)

Opt. Quantum Electron. (1)

A. Caprara and G. C. Reali, Opt. Quantum Electron. 24, 1001 (1992).
[CrossRef]

Rev. Laser Eng. (1)

J. J. Zayhowski, Rev. Laser Eng. 26, 841 (1998).
[CrossRef]

Other (1)

A. E. Siegman, Lasers (University Science, Mill Valley, Calif., 1986), p. 786.

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Figures (4)

Fig. 1
Fig. 1

Far-field pulse divergence: a, In the beginning of the pulse, the laser-mode size is small, giving rise to a wide beam in the far zone. b, When the intensity in the cavity is high, the saturable absorber is strongly bleached, resulting in a larger laser mode and a smaller far-field divergence. c, As the intensity decreases in the trailing edge of the pulse, the saturable absorber is still bleached, and the laser-mode size is not changed.

Fig. 2
Fig. 2

Far-zone effects of decreasing beam divergence and a Gaussian laser intensity distribution in time. The exaggeration of the change in laser-mode size illustrates the behavior of the far-field pulse maximum. At the onset of the pulse the far-zone beam width is at its maximum, and consequently the beginning of the pulse at the off-axis position is stronger than the end of the pulse in the same position.

Fig. 3
Fig. 3

Experimental setup: A, reference plane; B, measuring plane (fiber I can be moved around in this plane, allowing measurements at different off-axis positions); C, pellicle beam splitter; D, variable attenuator; E, 1-GHz Si detector; F, oscilloscope; G, computer; H, measuring fiber; I, reference fiber.

Fig. 4
Fig. 4

Measured time difference in pulse arrival in the x direction and the y direction as a function of relative radius w/w0. The solid curve is a numerical simulation that corresponds to a 3-ns Gaussian pulse during which the laser-mode width in the cavity increases by 13%.

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