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Advancements in laser glass compositions and manufacturing techniques has allowed the development of a new category of high-energy and high-power laser systems which are being used in various applications, such as for fundamental research, material processing and inertial confinement fusion (ICF) technologies research. A ceramic laser is a remarkable revolution in solid state lasers. It exhibits crystalline properties, high yields, better thermal conductivity, a uniformly broadened emission cross-section, and a higher mechanical constant. Polycrystalline ceramic lasers combine the properties of glasses and crystals, which offer the unique advantages of high thermal stability, excellent optical transparency, and the ability to incorporate active laser ions homogeneously. They are less expensive and have a similar fabrication process to glass lasers. Recent developments in these classes of lasers have led to improvements in their efficiency, beam quality, and wavelength versatility, making them suitable for a broad range of applications, such as scientific research requiring ultra-fast laser pulses, medical procedures like laser surgery and high-precision cutting and welding in industrial manufacturing. The future of ceramic lasers looks promising, with ongoing research focused on enhancing their performance, developing new doping materials and expanding their functional wavelengths. The ongoing progress in high-power ceramic lasers is continuously expanding the limits of laser technology, therefore allowing the development of more powerful and efficient systems for a wide range of advanced and complex applications. In this paper, we review the advances, limitations and future perspectives of ceramic lasers. [ABSTRACT FROM AUTHOR]

The phase diagram of sodium chloride (NaCl) under laser shock compression has been studied at Linac Coherent Light Source (LCLS) at the x-ray free-electron laser facility. Both solid–solid (B1 → B2) and solid–liquid (B2 → liquid) transitions have been observed along the Hugoniot over nanosecond time scales. By combining structural measurements through in situ x-ray diffraction, pressure determination through velocimetry, and a thermal equation-of-state, the shock-compressed data are used to constrain the phase diagram of NaCl. Transformation into the B2 phase is found to occur at 28(2) GPa, and B2–liquid coexistence is observed between 54(4) and 66(6) GPa, with near full melt at 66(6) GPa. Late-time pressure release from an initial shocked B2-state results in a B2 → B1 back transformation. Our results show agreement with previous static compression data, suggesting that the time scale for melting is very rapid and that equilibrium states in NaCl are being accessed over nanosecond time scales. A multiphase equation-of-state description of NaCl incorporated into a one-dimensional hydrocode is used to interpret pressure and temperature evolution over these rapid time scales. [ABSTRACT FROM AUTHOR]

Combining an x-ray free electron laser with a high-power laser driver enables the study of equations-of-state, high strain-rate deformation processes, structural phase transitions, and transformation pathways as a function of pressure to hundreds of GPa along different thermodynamic compression paths. Future high repetition-rate laser operation will enable data to be accumulated at >1 Hz, which poses a number of experimental challenges, including the need to rapidly replenish the target. Here, we present a combined shock compression and an x-ray diffraction study on epoxy (50% vol.)-crystalline grains (50% vol.) slurry targets, which can be fashioned into extruded ribbons for high repetition-rate operation. For shock-loaded NaCl-slurry samples, we observe pressure, density, and temperature states within the embedded NaCl grains consistent with observations from shock-compressed single-crystal NaCl. [ABSTRACT FROM AUTHOR]

Enteric fever can have wide clinical presentation in humans. We report few rare complications of enteric fever such as secondary hemophagocytic lymphohistiocytosis, liver abscess, encephalopathy, and myopericarditis. Interestingly none of these cases are easy to recognize in early days in far flung remote areas where facilities are lacking. In our observance, first case was of 59-year-old male, who presented with acute febrile illness, thrombocytopenia, and hepatosplenomegaly. The patient had progressive pancytopenia with clinical deterioration. A diagnosis of secondary hemophagocytic lymphohistiocytosis was made and managed. The second case presented as fever with acute abdomen, which was due to pyogenic liver abscess caused by Salmonella typhi (S. typhi). Third case was 65-year-old female who presented with fever associated with neuropschychiatric and cerebeller signs. She was diagnosed as enteric encephalitis and managed with antibiotics along with corticosteroids. Fourth case was of 22-year-old female with blood culture positive for S. typhi and positive serum Widal test who after 3 days of treatment developed sudden cardiogenic shock and echocardiography confirmed presence of myopericarditis with mild pericardial effusion. [ABSTRACT FROM AUTHOR]

The microscopic and dynamic response of the atactic polystyrene molecules under shock compression at laser power density of 4.9 GW/cm2 was studied using time-resolved Raman spectroscopy. The shock pressure estimated in the polystyrene sample was 2 GPa, and the temporal and wavenumber resolutions in these experiments were 3 ns and 3 cm−1, respectively. The shocked polystyrene showed a blue shift of 5 and 7 cm−1 for the 1004 cm−1 (C-C-C ring bending mode ν12) and 1606 cm−1 (C-C ring stretching mode [ABSTRACT FROM AUTHOR]

We have carried out Raman spectroscopic measurements on atactic polystyrene (aPS) under shock compression up to 2GPa. Observed wavenumber shifts of Raman active modes have been used to determine their Grüneisen parameters and bond anharmonicities. Raman mode at 798 cm-1 displays maximum blue shift of 4.95 cm-1/GPa. Our observed wavenumber shifts under shock compression are found to be consistent with the earlier results obtained under hydrostatic pressure. We have also evaluated pressure through 1D radiation hydrodynamic simulations, and the results are found to be in good agreement with the experimental values. The pressure induced wavenumber shifts and line width changes of the present study can be utilized as a gauge for pressure measurement because of laser induced shock front. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]