Volume 56, number 3 OPTICS COMMUNICATIONS 1 December 1985 c: L r 125ps ---I Fig. 4. Streak camera trace of amplified and compressed pulse with a reflection from an ctalon. Separation between pulses is 125 ps. Pulsewidth is limited by the streak camera response at 2 ps.
long fiber lengths required to linearize the chirp can then be used and the pulses can be compressed with- out wings. Regardless of pulse distortion due to spectral and gain saturation of the amplifier, the pulse was com- pressed after amplification, indicating that the pulse remains linearly chirped. The pulsewidth of the am- plified compressed pulses was measured using a streak camera. Fig. 4 shows a streak camera trace of a pulse and a reflection from an etalon. The spacing between the two pulses is 125 ps. The FWHM of the pulse is 2 ps which is limited by the streak camera response. In the future, we will be improving the mode-lock- ing of the laser, such that the initial pulsewidth is less than 100 ps. A pulsewidth of 0.5 ps could then be achieved after compression. Also, we are planning to add successive amplifiers in order to have pulse en- ergies of a few hundred millijoules. Conceivably, this technique could be used to generate subpicosecond pulses, with energies at the Joule level. We will be studying the amplification of these chirped pulses to determine the effects of spectra1 and gain saturation, on the chirp linearity. In particu- lar, we will be looking for the effects of gain sweep- ing. It is important to note that this technique can be
used to amplify any short pulse, for instance that from a short pulse dye laser. The short pulse can be stretched by the GVD of a single-mode fiber. The pulse can then be amplified and recompressed to its original pulsewidth, in a completely analogous man- ner to the radar transmission. In conclusion, we have shown that by first stretch- ing a chirped optical pulse and then amplifying before compressing, high peak power pulses can be achieved. To date, we have produced 2 ps pulses with an energy of 1 mJ.
The authors wish to thank Steve Williamson for his help in developing the concept as well as Phillipe Bado and Marcel Bouvier for their technical support. We would also like to acknowledge Vienkata Bhaga- vatula of Corning Glass Works for giving us the fiber which made this work possible. This work was supported by the U.S. Department of Energy Office of Inertial Fusion under agreement No. DE-FC08-85DP40200 and by the Laser Fusion Feasibility Project at the Laboratory for Laser Ener- getics which has the following sponsors: Empire State Electric Energy Research Corporation, General Elec- tric Company, New York State Energy Research and Development Authority, Northeast Utilities Service Company, Ontario Hydro, Southern California Edison Company, The standard Oil Company, and the Uni- versity of Rochester. Such support does not imply endorsement of the content by any of the above par- ties.
References
[l] E. Brookner, Scientific American 252 (1985) 2. [2] B. Nikolaus and D. Grischkowsky, Appl. Phys. Lett. 42 (1983) 1. [3] E.B. Treaty, IEEE J. Quant. Electron. QE-5 (1969) 454. [4] G. Mourou and S. Williamson, Patent Application No. 570,148, filed January 12,1984. [S] J. Desbois, F. Gires and P. Tournois, IEEE J. Quant. Electron. QE-9 (1973) 213. [6] B. Kolner, J.D. Kafka, D.M. Bloom and T.M. Baer, post- deadline paper ThE29-1, Topical Meeting on Ultrafast phenomena, Monterey, California (1984).
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