Tetragonal tungsten bronze structure potassium lithium niobate (KLN) crystals pr omise as a potentially useful material for nonlinear optical applications,especi ally,for blue laser radiation by second harmonic genera...Tetragonal tungsten bronze structure potassium lithium niobate (KLN) crystals pr omise as a potentially useful material for nonlinear optical applications,especi ally,for blue laser radiation by second harmonic generation (SHG).We have grown KLN single crystals by TSSG method using different melt compositions and studied the properties of second harmonic generation (SHG).The crystals have the conten ts of Nb 2O 5 in the range of 51 54% and Li 2O in the range of 17.5 20% and a non critical SHG phase matching wavelength being a wide range from 843 and 9 67 nm. The dependence of temperature and SHG phase match wavelength and the temp erature acceptance were measured by a cw Ti∶Al 2O 3 laser(Spectra Physics M odel 3900S).The results show a linear relationship between phase match wavelengt h and temperature and a about 4℃ temperature acceptance.The homogeneity on a KL N crystal sample of 4×5×8mm was characterized where the SHG phase match wavele ngth changed within 887.8 and 887.5nm . With comparing the wavelength accepta nce being 0.5nm,the result suggests that the homogeneity is good. The dependence bet ween crystal composition,crystal lattice constants and SHG properties will be di scussed.展开更多
In this paper,ferroelectric tetragonal tungsten bronze type potassium lithium niobate(KLN)crystal with a size of 20mm×8mm×43mm was grown from a melt with a composition of 32mol% K 2CO 3,24mol% Li 2CO 3 and 4...In this paper,ferroelectric tetragonal tungsten bronze type potassium lithium niobate(KLN)crystal with a size of 20mm×8mm×43mm was grown from a melt with a composition of 32mol% K 2CO 3,24mol% Li 2CO 3 and 44mol% Nb 2O 5 by the top seeded solution growth (TSSG)method.The KLN crystal as grown along [110]axis has a perfect crystal melt interface dominated by {110} and {210} facets.Lattice constants were measured by X ray diffraction (XRD) analysis performed on {001}and {110}natural faces of single crystal samples.The anisotropic thermal expansion behavior of the crystal was also studied along [001] and [110] axes,respectively by using a Shimadzu TMA 50 thermomechnical analyzer.For the purpose of crystal poling,the dependence of crystal capacitance vs.temperature in both heating and cooling cycles was measured and the ferroelectric Curie temperature was determined to be 514℃.The crystal was poled at 506℃ with a dc field of about 250 V/cm along the c axis of the sample,for a time corresponding to about 1.5 h/cm.The blue second harmonic generation (SHG)characteristics of the KLN crystal were investigated by using a 3900s Ti∶sapphire CW tunable laser.Blue laser light at wavelength 432nm was obtained by the non critical phase matching (NCPM)SHG at room temperature.Based on the wavelength and temperature tuning curves for the NCPM SHG,the wavelength acceptance and temperature acceptance of this KLN crystal were measured.The crystal property homogeneity along the <110>growth axis was also studied by measuring the room temperature NCPM wavelength at different growth positions.展开更多
文摘Tetragonal tungsten bronze structure potassium lithium niobate (KLN) crystals pr omise as a potentially useful material for nonlinear optical applications,especi ally,for blue laser radiation by second harmonic generation (SHG).We have grown KLN single crystals by TSSG method using different melt compositions and studied the properties of second harmonic generation (SHG).The crystals have the conten ts of Nb 2O 5 in the range of 51 54% and Li 2O in the range of 17.5 20% and a non critical SHG phase matching wavelength being a wide range from 843 and 9 67 nm. The dependence of temperature and SHG phase match wavelength and the temp erature acceptance were measured by a cw Ti∶Al 2O 3 laser(Spectra Physics M odel 3900S).The results show a linear relationship between phase match wavelengt h and temperature and a about 4℃ temperature acceptance.The homogeneity on a KL N crystal sample of 4×5×8mm was characterized where the SHG phase match wavele ngth changed within 887.8 and 887.5nm . With comparing the wavelength accepta nce being 0.5nm,the result suggests that the homogeneity is good. The dependence bet ween crystal composition,crystal lattice constants and SHG properties will be di scussed.
文摘In this paper,ferroelectric tetragonal tungsten bronze type potassium lithium niobate(KLN)crystal with a size of 20mm×8mm×43mm was grown from a melt with a composition of 32mol% K 2CO 3,24mol% Li 2CO 3 and 44mol% Nb 2O 5 by the top seeded solution growth (TSSG)method.The KLN crystal as grown along [110]axis has a perfect crystal melt interface dominated by {110} and {210} facets.Lattice constants were measured by X ray diffraction (XRD) analysis performed on {001}and {110}natural faces of single crystal samples.The anisotropic thermal expansion behavior of the crystal was also studied along [001] and [110] axes,respectively by using a Shimadzu TMA 50 thermomechnical analyzer.For the purpose of crystal poling,the dependence of crystal capacitance vs.temperature in both heating and cooling cycles was measured and the ferroelectric Curie temperature was determined to be 514℃.The crystal was poled at 506℃ with a dc field of about 250 V/cm along the c axis of the sample,for a time corresponding to about 1.5 h/cm.The blue second harmonic generation (SHG)characteristics of the KLN crystal were investigated by using a 3900s Ti∶sapphire CW tunable laser.Blue laser light at wavelength 432nm was obtained by the non critical phase matching (NCPM)SHG at room temperature.Based on the wavelength and temperature tuning curves for the NCPM SHG,the wavelength acceptance and temperature acceptance of this KLN crystal were measured.The crystal property homogeneity along the <110>growth axis was also studied by measuring the room temperature NCPM wavelength at different growth positions.
