Effect of Strontium Ion on the Growth and Second-Harmonic Generation Properties of GdCa_(4)O(BO_(3))_(3) Crystal

Large sized and optical quality GdCa_(4)O(BO_(3))_(3)(GdCOB)crystal with calcium partially substituted by strontium(Sr)ions was grown for the first time.The x-ray powder diffraction shows that the Sr ion has an effect on the cell parameters of the GdCOB crystal Second-harmonic generation(SHG)experiments were performed on the Sr:GdCOB and GdCOB crystals along the spatial phase-matching direction.The results show that the cw green laser output power is 1.04 W when the laser diode pump power is 10 W in the Nd:YVO_(4)/Sr:GdCOB intracavity laser.Considering the slope efficiency of Nd:YVO_(4) and the fundamental laser in cavity,the intracavity SHG conversion efficiency of the GdCOB crystal is 21%while it is 24%for the Sr:GdCOB crystal,the SHG conversion efficiency is improved by 14%.The effect of the Sr ions on the nonlinearity of the GdCOB crystal is also discussed by using the anion group theory.

A New Nonlinear Optical Crystal GdCa_(4)O(BO_(3))_(3)

Large size and high quality single crystals GdCa_(4)O(BO_(3))_(3) have been grown from platinum crucible under air atmosphere by the conventional rf-heating Czochralski method.The crystal growth conditions,growth habits,and transmission spectra were investigated.The crystal is transparent in the visible and near-infrared region(320-2600nm).It has a good second harmonic generation phase-matching condition.The phase-matching experiment result is well consistent with the theoretical one.The frequency-doubling efficiency is 26.7% in the phase-matching angles θ=45o and ø=45.1o direction.

Growth and Second-Harmonic-Generation Properties of Tm^(3+), Yb^(3+), Bi^(3+) and Li^(+) Doped GdCa_(4)O(BO_(3))_(3) Crystals

The rare-earth ions(Yb^(3+),Tm^(3+))and Li^(+),Bi^(3+)ions doped GdCa_(4)O(BO_(3))_(3) crystals were grown using the Czochralski pulling method.The second-harmonic-generation conversion efficiencies of the GdCOB:Yb and GdCOB:Tm crystals are 31.3%and 33.3%,respectively,while the undoped GdCOB crystal is 27.9%.The conversion efficiencies of Yb^(3+),Tm^(3+)doped GdCOB are improved by 12%and 19%,respectively,compared to that of the undoped one.The conversion efficiencies of Li^(+),Bi^(3+)doped GdCOB crystals are 33%and 38.3%,which are improved by 15%and 37%as compared to that of the undoped crystal.The results are discussed using the anion group theory.

Studies on Lead Tungstate Crystal

The growth of lead tungstate(PWO)single crystals and their luminescence properties such as light yield,scintillation decay time,and transmittance were reported.The colourless PWO single crystal has been obtained by using the presyntheses powder.Ba,Nb,and Mg ions were doped in the crystals and the Ba-doped crystal has a relatively short decay time.Annealed crystal was found having a better transmission spectrum than that of unannealed one.

Low Temperature Phase Transition of a Crystal in the Potassium Lithium Niobate System

A potassium lithium niobate crystal with tetragonal tungsten bronze structure was prepared by the Czochralski technique.The dielectric and pyroelectric properties were investigated in the temperature range of 300 to 10 K.A broadened ferroelectric-ferroelectric transition between phases with space group 4mm and space group m was found at about 80K.