A lO-kJ PW laser (LFEX) is under construction for the FlREX-I program. This paper reports a desigri overview of LFEX, the technological development of a large-aperture arrayed amplifier with modified four-pass architecture, wavefront correction, a large-aperture Faraday rotator with a superconducting magnet, a new pulse compressor arrangement,. and focus control.

The principal refractive indices and the thermal coefficients for a LiNbO(3) crystal doped with 5 mol. % MgO have been measured by a minimum-deviation method for the wavelengths of 0.53975, 0.6328, 1.0795, and 1.3414, microm in the temperature range 20-154.5 degrees C. The constants of modified Sellmeier equations are all given in the described temperature range. The measured results were used to calculate the type I critical phase-matching angles for 1.0795- and 1.3414-microm second-harmonic generation at room temperature and the noncritical phase-matching temperature for 1.0795-microm second-harmonic generation for LiNbO(3) crystal doped with 5 mol. % MgO. The values obtained agree well with the experimental results.

Segmented (tiled) grating arrays are being intensively investigated for petawatt-scale pulse compression due to the expense and technical challenges of fabricating monolithic diffraction gratings with apertures of over 1 m. However, the considerable freedom of motion among grating segments complicates compression and laser focusing. We constructed a real compressor system using a segmented grating for an 18 cm aperture laser beam of the Gekko MII 100 TW laser system at Osaka University. To produce clean pulse shapes and single focal spots tolerant of misalignment and groove density difference of grating tiles, we applied a new compressor scheme with image rotation in which each beam segment samples each grating segment but from opposite sides. In high-energy shots of up to 50 J, we demonstrated nearly Fourier-transform-limited pulse compression (0:5 ps) with an almost diffraction-limited spot size (20 μm).

Identifying the drought-tolerance traits of plant species originating from a moisture gradient will increase our understanding of the differences and similarities in plant drought tolerance. However, which traits can be used to evaluate drought tolerance remain an open question. Here, we conducted a common-garden experiment on 37 shrub species originating from desert to humid regions. The correlations between plant traits and the native environmental conditions were studied. Leaf sizes and Huber values were significantly correlated with most climate variables of the shrubs’ origins. The osmotic potentials at full turgor (π100), turgor loss point (ΨTLP), and midday leaf water potential (Ψmid) were significantly correlated with most climate variables of their origins. We proposed using leaf sizes, Huber values, and ΨTLP as predictors of drought tolerance across shrub species and shrub biomes. Statistically significant correlations were found between π100, ΨTLP, and specific leaf area (SLA). However, owing to the weak correlations between SLA and the climate variables of the shrubs origins and between Huber values and leaf size and turgor loss traits, it was difficult to integrate leaf morphological traits with physiological traits to find a simple way to accurately quantify drought-tolerance-related differences among these shrub species.