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Fig. 10-3 Diagram of the pulse shape of the T3 laser of 10 TW class

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Fig. 10-4 Technologies attained during development of the present T3 laser

A high-power laser system with an output power of 1 TW (1012 W) small enough to be set on a table is called the Table-Top-Terawatt laser, or the T3 for short. In order to realize such high power in a small laser system it is first necessary to realize an extremely short pulse. Application possibilities for such a small high-power laser with an extremely short pulse are immeasurable. For example, an x-ray laser or a high-field particle accelerator could be realized by taking advantage of its small size and high performance for use in the fields of medicine and biochemical materials research. The T3 laser was established on the basis of the chirp pulse amplification method by which a high-power short-pulse laser is generated from a low-intensity, short-pulse laser through the process of pulse expansion, amplification and compression. Realization of a high-power laser was, however, still difficult because with an increase in laser power, "nonlinearity" (where the behavior of the laser beam is affected by the laser itself) becomes dominant and optical components are broken by the high power density. Consequently an extremely high-power laser with a pulse width shorter than about 20 fs (1 fs=10-15 s) had not previously been realized. Last year we succeeded in developing a T3 laser with a peak output power of 4 TW and a pulse width of 18 fs, in cooperation with a team from the University of California. Furthermore, we also succeeded in generating laser light with a peak output power of 9.5 TW and a pulse width of 16.6 fs (Fig. 10-3). This pulse width is the world record for the T3 laser in 10 TW class. This success has been attained by establishing technologies to adjust the pulse expander and the compressor with very high accuracy, to suppress the pulse expansion at extremely high output power, and to strictly stabilize the laser output power (Fig. 10-4). We plan to systematically develop a 100 TW and a 1,000 TW laser in the future.

Reference K. Yamakawa et al., All-Solid-State Mirror-Dispersion-Controlled Sub-10 fs Ti : Sapphire Laser, Jpn. J. Appl. Phys., 35, L989 (1996).

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