During the crystal growth of Nd,Cr∶GSGG by Czochralski method,in some cases eutectic reaction occurred in the nether region of the crystal,and the boule was divided into two obvious different parts,which is upper Nd...During the crystal growth of Nd,Cr∶GSGG by Czochralski method,in some cases eutectic reaction occurred in the nether region of the crystal,and the boule was divided into two obvious different parts,which is upper Nd,Cr∶GSGG crystal and the nether coexisting Nd,Cr∶GSGG and GdScO_(3).By X-ray powder diffraction,the structure change of NdCr∶GSGG crystal ofΦ27 mm×120 mm with eutectic along its grown direction<111>was studied.By the least square method and extrapolation function f=sinθ-sinθ^(1-t)(t is an adjustable parameter),the lattice parameters of Nd,Cr∶GSGG and additional GdScO_(3)phase were computed.The results indicate that the lattice parameters of Nd,Cr∶GSGG increase along its growth direction,which changes from a=(1.25650±0.00007)nm of the top to(1.25798±0.00010)nm of the bottom.In the process of Nd,Cr∶GSGG growth,Gd^(3+)in Nd,Cr∶GSGG is partly replaced by Nd^(3+)with larger ionic radii,and the volatilization of Ga component results in its composition variance,which cause the lattice parameters increase along growth direction.In the eutectic section,there are the Nd,Cr∶GSGG and the second phase orthorhombic GdScO_(3).The lattice parameters of GdScO_(3)are a=0.5443±0.0007,b=0.5699±0.0005 and c=(0.7865±0.0009)nm,and that of Nd,Cr∶GSGG is(1.25798±0.00010)nm.In the final growth stage,excessive volatilization of Ga composition during the crystal growth causes the growth melt deflect of the Nd,Cr∶GSGG solid solution range seriously,and results in the eutectic reaction,and the outgrowth of Nd,Cr∶GSGG and GdScO_(3).So it is necessary to decrease the effect of gallium volatilization during the growth in order to avoid eutectic growth and obtain a high-quality Nd,Cr∶GSGG.展开更多
Diode end-pumped solid-state lasers have the potential to yield high quality laser beams with high efficiency for laser range finding and warning receiver applications as well as day and night military laser designati...Diode end-pumped solid-state lasers have the potential to yield high quality laser beams with high efficiency for laser range finding and warning receiver applications as well as day and night military laser designation systems. In this paper we presents theoretical calculations using Advanced Dynamics Professional LASCAD software and experimental studies for a high power pigtailed fiber diode laser module of 8 W operating at 808 nm with a specially designed high efficiency cooling system, end pumped high-efficiency Nd:YVO4 laser of 3 × 3 × 10 mm rod and overall cavity length of 44 mm. To the best of our knowledge a self Q-switching effects was generated in Nd:YVO4 laser by changing the cavity dimensions and the position of the intracavity KTP crystal at certain regime of operation for the first time, in which the cavity length is reduced to be 30 mm and the distance between Nd:YVO4 rod and KTP crystal is only 1mm. Self Q-switched laser pulse at 532 nm with high peak power of 96 W, pulse width of 88 ns at FWHM and repetition rate of 400 kHz was achieved. Experimental studies of a passive Q-switched Nd:YVO4 laser using Cr:YAG crystal with three different transmissions of 30%, 40% and 70% were investigated. Passive Q-switched laser pulse at 1064 nm and narrow line width of less than 1.5 nm with highest peak power of nearly 18 kW, short pulse width of less than 4 ns at FWHM and higher repetition rate of 45 kHz using Cr:YAG with transmission of 30% was achieved for the first time.展开更多
We first experimentally demonstrate a laser-diode end-pumped self-Q-switched and mode-locked Nd,Cr：YAG green laser with a KTP crystal as the intra-cavity frequency doubler. The device produces an average output power...We first experimentally demonstrate a laser-diode end-pumped self-Q-switched and mode-locked Nd,Cr：YAG green laser with a KTP crystal as the intra-cavity frequency doubler. The device produces an average output power of 680 mW at 532 nm. The corresponding pulse width of the Q-switched envelope of the green laser is 170 ＋ 20 ns. The mode-locked pulses have a repetition rate of approximately 183 MHz and the average pulse duration is estimated to be around sub-nanosecond. It is found that the intra-cavity frequency doubling greatly improves the modulation depth and stability of the mode-locked pulses within the Q-switched envelope.展开更多
Absorption, excitation and emission spectra as well as decay time measurements at 10, 77, and 300 K were perfumed for Gd3Sc2Ga3O12 garnet single-crystal doped with Cr^3＋ and Nd^3＋ ions. Strong reabsorption of Cr3＋ ...Absorption, excitation and emission spectra as well as decay time measurements at 10, 77, and 300 K were perfumed for Gd3Sc2Ga3O12 garnet single-crystal doped with Cr^3＋ and Nd^3＋ ions. Strong reabsorption of Cr3＋ emission by Nd3＋ absorption lines was ob- served. The assignments of f-f and d-d transitions were proposed. The broad emission band of chromium ions is an indication that weak/intermediate crystal field strength is present at the Cr3＋ site.展开更多
基金Project supported National Natural Science Foundation of China(60478025,50472104)
文摘During the crystal growth of Nd,Cr∶GSGG by Czochralski method,in some cases eutectic reaction occurred in the nether region of the crystal,and the boule was divided into two obvious different parts,which is upper Nd,Cr∶GSGG crystal and the nether coexisting Nd,Cr∶GSGG and GdScO_(3).By X-ray powder diffraction,the structure change of NdCr∶GSGG crystal ofΦ27 mm×120 mm with eutectic along its grown direction<111>was studied.By the least square method and extrapolation function f=sinθ-sinθ^(1-t)(t is an adjustable parameter),the lattice parameters of Nd,Cr∶GSGG and additional GdScO_(3)phase were computed.The results indicate that the lattice parameters of Nd,Cr∶GSGG increase along its growth direction,which changes from a=(1.25650±0.00007)nm of the top to(1.25798±0.00010)nm of the bottom.In the process of Nd,Cr∶GSGG growth,Gd^(3+)in Nd,Cr∶GSGG is partly replaced by Nd^(3+)with larger ionic radii,and the volatilization of Ga component results in its composition variance,which cause the lattice parameters increase along growth direction.In the eutectic section,there are the Nd,Cr∶GSGG and the second phase orthorhombic GdScO_(3).The lattice parameters of GdScO_(3)are a=0.5443±0.0007,b=0.5699±0.0005 and c=(0.7865±0.0009)nm,and that of Nd,Cr∶GSGG is(1.25798±0.00010)nm.In the final growth stage,excessive volatilization of Ga composition during the crystal growth causes the growth melt deflect of the Nd,Cr∶GSGG solid solution range seriously,and results in the eutectic reaction,and the outgrowth of Nd,Cr∶GSGG and GdScO_(3).So it is necessary to decrease the effect of gallium volatilization during the growth in order to avoid eutectic growth and obtain a high-quality Nd,Cr∶GSGG.
文摘Diode end-pumped solid-state lasers have the potential to yield high quality laser beams with high efficiency for laser range finding and warning receiver applications as well as day and night military laser designation systems. In this paper we presents theoretical calculations using Advanced Dynamics Professional LASCAD software and experimental studies for a high power pigtailed fiber diode laser module of 8 W operating at 808 nm with a specially designed high efficiency cooling system, end pumped high-efficiency Nd:YVO4 laser of 3 × 3 × 10 mm rod and overall cavity length of 44 mm. To the best of our knowledge a self Q-switching effects was generated in Nd:YVO4 laser by changing the cavity dimensions and the position of the intracavity KTP crystal at certain regime of operation for the first time, in which the cavity length is reduced to be 30 mm and the distance between Nd:YVO4 rod and KTP crystal is only 1mm. Self Q-switched laser pulse at 532 nm with high peak power of 96 W, pulse width of 88 ns at FWHM and repetition rate of 400 kHz was achieved. Experimental studies of a passive Q-switched Nd:YVO4 laser using Cr:YAG crystal with three different transmissions of 30%, 40% and 70% were investigated. Passive Q-switched laser pulse at 1064 nm and narrow line width of less than 1.5 nm with highest peak power of nearly 18 kW, short pulse width of less than 4 ns at FWHM and higher repetition rate of 45 kHz using Cr:YAG with transmission of 30% was achieved for the first time.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 60278024 and 60438020）.
文摘We first experimentally demonstrate a laser-diode end-pumped self-Q-switched and mode-locked Nd,Cr：YAG green laser with a KTP crystal as the intra-cavity frequency doubler. The device produces an average output power of 680 mW at 532 nm. The corresponding pulse width of the Q-switched envelope of the green laser is 170 ＋ 20 ns. The mode-locked pulses have a repetition rate of approximately 183 MHz and the average pulse duration is estimated to be around sub-nanosecond. It is found that the intra-cavity frequency doubling greatly improves the modulation depth and stability of the mode-locked pulses within the Q-switched envelope.
基金supported by Ministry of Science and Higher Education (N N507 372335)
文摘Absorption, excitation and emission spectra as well as decay time measurements at 10, 77, and 300 K were perfumed for Gd3Sc2Ga3O12 garnet single-crystal doped with Cr^3＋ and Nd^3＋ ions. Strong reabsorption of Cr3＋ emission by Nd3＋ absorption lines was ob- served. The assignments of f-f and d-d transitions were proposed. The broad emission band of chromium ions is an indication that weak/intermediate crystal field strength is present at the Cr3＋ site.
