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The main temporal and energetic characteristics of an ultrabroadband nanosecond Ti 3ϩ :sapphire laser are measured. The laser resonator employs a prism pair and a diaphragm creating a ''spatially dispersive'' cavity, and then is allowed to maintain the lasing conditions simultaneously for different spectral components in different areas of the active element. Second-harmonic radiation from a Q-switched YAG:Nd 3ϩ laser with a 532-nm oscillating wavelength and up to 210 mJ of pulse energy was utilized as a pumping source. The ultrabroadband laser was transversely pumped and operated simultaneously in 685-to 955-nm region with a minimum pulse duration of 25 ns, pulse energy of up to 17.8 mJ, a pulse repetition rate of 10 Hz, and 8.5% real pumping to lasing efficiency. Oscillation build-up time was 19.8 ns at a 775-nm wavelength and was varied for different spectral components by only 7 ns in the 700-to 912-nm region. © 1999 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(99)01104-6] Downloaded From: http://opticalengineering.spiedigitallibrary.org/ on 05/15/2015 Terms of Use: http://spiedl.org/terms

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A ten-parameter quasi-harmonic semimicroscopic model for the low-frequency lattice dynamics of betaine calcium chloride dihydrate is presented. The choice of the relevant variables and interaction terms of the model potential is mainly based on the known crystallographic data, while the values of the quasi-harmonic force constant parameters are adjusted to our recent inelastic neutron scattering data. The parameter with the largest temperature derivative is determined and the origin of its temperature renormalization is discussed.