Gerard Mourou

TL;DR: In this article, the possibility of using laser wakefield acceleration (LWFA) as the source of low-energy electron radiation for endoscopic and intracloud imaging has been explored.

Abstract: Recently there has been increased interest in regenerative amplification of short pulses in titanium-doped sapphire at wavelengths considerably shorter than 800 nm.'r2 The motivation is the use of the third harmonic of near IR radiation to seed KrF excimer laser amplifiers for the generation of ultrashort ultraviolet pulses with peak powers as high as 1 TW.' However, in the cases referenced above, the authors report difficulty in sustaining amplification at these wavelengths without physically impeding the cavity from lasing at 800 nm by means of a knife edge. In this paper we will present the details of a regenerative amplifier that not only oscillates unseeded at 745 nm, but has demonstrated tunability in its oscillation over a range from 735 nm to beyond 800 nm with one set of mirrors. A diagram of the cavity is shown in Fig. 1. The cavity design is based on a 2.5-m-long half symmetric confocal arrangement with the spherical mirror having a 5 m radius of curvature. All optics are designed for optimum performance at 745 nm. The prisms are SFlO and are placed with an apex separation of 28 cm to compensate the positive GVD introduced by the other intercavity elements. The tunability is achieved by the use of the prism pair in the cavity in combination with the spherical mirror in that end of the cavity. At the curved mirror, the spectrum is spatially dispersed as a result ofthe prism pair. Since the mirror has a finite radius of curvature, only a narrow band of wavelengths are retroreflected through the cavity and are therefore amplified. Experimentally, there is an optimum ratio of mirror radius R to overall cavity length L, which we find to be approximately 2. Higher ratios result in a loss of tunability, while a lower ratio results in severe spectral narrowing. Figure 2 shows the unseeded, Q-switched spectral output of the amplifier cavity. We realize that this method of tuning limits the pulse duration that may be amplified in this cavity as a result of spectral narrowing. However, since we are not interested in pulse durations shorter than -100 fs because of the finite bandwidth of excimer lasers, we are unaffected by this limitation. The amplifier is pumped with 25 mJ (+-0.2 mJ) from a frequency-doubled Nd:YAG laser, 60607-7059.

TL;DR: In the near future, CPA will be applied to large laser systems such as NOVA to produce petawatt pulses (1 kJ in a 1 ps pulse) with focused intensities exceeding 10/sup /plus/21/ W/cm/sup 2 as discussed by the authors.

TL;DR: In this article, the design of a single ultra intense laser beamline delivering 25PW pulses at one shot per minute was presented as the first step of an ultra intense high field science European project (extreme light infrastructure).

TL;DR: In this article, the ICAN project is looking toward the next frontier of high-energy laser physics: building efficient, high-average-power lasers, which could transform nuclear medicine, detect nuclear waste and form the basis for the next great particle accelerator.