Abstract

Ultrashort pulsed laser material processing is a new micromachining method that is gaining interest. Its capability of submicrometer machining has been proved. To obtain high speed and highly flexible beam steering, a two-axis acousto-optic deflector is employed. However, dispersion associated with acoustic-optic interaction will cause serious spatial deformation on the writing spot. The compensation for dispersion is proposed and studied. Experiments show promising results. An additional advantage of the proposed compensation method is that it can also precisely control the pulse number, and, hence improve the quality of ablation.

© Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |

  1. X. Liu, D. Du. and G. Mourou, "Laser ablation and micromachining with ultrashort laser pulses," IEEE J. Quantum Electron. 33, 1706-1716, (1997).
    [CrossRef]
  2. P. P. Pronko, S. K. Dutta, J. Squier, J. V. Rudd, D. Du, and G. Mourou, "Machining of submicron holes using a femtosecond laser at 800nm," Opt. Commun. 114, 106-110 (1995).
    [CrossRef]
  3. X. Liu, "Submicron lines in thin metal films micromachined by an ultrafast laser oscillator," Conference on Lasers and Electro-Optics (CLEO/U.S.), Vol. 6 of 1998 OSA Technical Digest Series (Optical Society of America, Washington, D.C. 1998), p511.
  4. P. C. Allen and P. Buck, "Resolution performance of a 0.6NA, 364nm laser direct writer," Proc. SPIE, 1264, 454-465 (1990).
    [CrossRef]

Other

X. Liu, D. Du. and G. Mourou, "Laser ablation and micromachining with ultrashort laser pulses," IEEE J. Quantum Electron. 33, 1706-1716, (1997).
[CrossRef]

P. P. Pronko, S. K. Dutta, J. Squier, J. V. Rudd, D. Du, and G. Mourou, "Machining of submicron holes using a femtosecond laser at 800nm," Opt. Commun. 114, 106-110 (1995).
[CrossRef]

X. Liu, "Submicron lines in thin metal films micromachined by an ultrafast laser oscillator," Conference on Lasers and Electro-Optics (CLEO/U.S.), Vol. 6 of 1998 OSA Technical Digest Series (Optical Society of America, Washington, D.C. 1998), p511.

P. C. Allen and P. Buck, "Resolution performance of a 0.6NA, 364nm laser direct writer," Proc. SPIE, 1264, 454-465 (1990).
[CrossRef]

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 (9)

Fig. 1.
Fig. 1.

Dispersion occurs after transmitting the AOD

Fig. 2.
Fig. 2.

Two axes dispersion

Fig. 3.
Fig. 3.

Principle of compensation for dispersion caused by AOD

Fig. 4.
Fig. 4.

Optimized Dispersion compensation. The final beam is corrected and compensated from the AOM. In the experiment, the tilting degree of the AOM lies approximately around 45°.

Fig. 5.
Fig. 5.

Dispersion along the bandwidth of driving frequency

Fig. 6.
Fig. 6.

Error of compensation along the bandwidth while the central frequency of AOM is 105MHz

Fig. 7.
Fig. 7.

Error of compensation along the bandwidth while the central frequency of AOM is 150MHz

Fig. 8.
Fig. 8.

Feature ablated on platinum film by dispersed laser spot (pulse energy of 60nJ).

Fig. 9.
Fig. 9.

Pit ablated on copper film. (pulse energy of 55nJ)

Equations (4)

Equations on this page are rendered with MathJax. Learn more.

θ = λ 0 f a / v a
Δ θ = λ 1 f a / v a λ 2 f a / v a = Δ λ f a / v a
Δ θ = ( Δ θ X 2 + Δ θ Y 2 ) 1 / 2
error = Δ θ AOM Δ θ

Metrics