Development of Low-Cost Composite Sandwich Structure for Missile Fuselage

Not Available A potentially efficient, tunable laser is proposed that, can, in principle, span the 2.8 to 3.4 micron wavelength range, a technically challenging area for atmospheric constituents and coherent wind measurements. The concept is based on a BaY2F8 crystal co-doped with thulium and dysprosium. Promising recent spectroscopic and dynamic measurements indicate excellent prospects for efficient energy transfer between the Tm3+ and the Dy3+ ions, since thulium absorbs in a region accessible to standard semiconductor arrays. The proposed laser offers, for the first time, the promise of a diode pumpable, direct, tunable emission in the 3 micron spectral region. The primary goal for this Phase I project is to demonstrate lasing from Tm,Dy:BaYF crystals pumped at around 800 nm. Several crystals will be grown to determine the effect of different ion concentrations on crystal level dynamics and multiphonon relaxation processes, followed by selection of samples with the most promising compositions for laser experiments. Techniques demonstrated with existing Ho,Tm:YLF lasers will be considered to address issues of power scaling and/or narrow-band operation. In addition, a new laser material, with even lower phonon energies than BYF, Dy: NaYF4 will be evaluated