Novel non-toxic nonlinear optical crystals for deep-ultraviolet laser generation
Experimental Condensed Matter Physics
Final Report Abstract
Deep-ultraviolet (DUV) nonlinear optical (NLO) crystals play a crucial role in the development of advanced scientific instruments. In this project, anew non-toxic NLO crystal Li18Cu3B12O30with large cell volume 593 Å3 was successfully synthesized by the unique high-pressure travelling-solvent floating-zone (TSFZ) furnace. This compound is phase-matchable at the wavelength of 1064 nm, and the SHG effect in Li18Cu3B12O30 is ca. 2 times than that of KH2PO4 (KDP), indicating that this compound has the potential to be a promising NLO crystal. The high-quality single crystal of non-toxic LiSrBaPO4 was successfully grown in the TSFZ furnace with the flux K3PO4. The morphologies, X-ray diffraction (XRD), Laue back-scattering, Infrared Spectroscopy (IR), Raman and thermal properties were fully investigated. In addition, a series of the borate crystalsLiAxByZO4 or 3(A and B =Sr or Ba, x and y = 0-1, Z = P, B, V) including Sr0.1Ba0.9LiPO4, LiSrVO4, LiBaPO4, LiSrPO4, LiBa(BO3)0.5(VO4)0.5, LiSr(PO4)0.8(VO4)0.2 etc., have also been synthesized. Among them, the obtained crystals Li18Cu3B12O30and LiSrBaPO4 have the potential to generate the DUV coherent output in photon energy of 6.2-7.8 eV. Besides the crystal growth activities, a Czochralski crystal growth molten salt system and an optimized Top Seeded Solution Growth (TSSG) single crystal growth equipment was successfully constructed, which are suitable for future large sizes and high optical quality NLO crystal growth. The project has been implemented as expected and there were no critical issues from the management point of view. The abovementioned adjustments to the original work plan reflect progress in knowledge gained within the project and in the literature. Direct management activities have not been funded by the grant.
