Passive Q switching and self-frequency Raman conversion in a diode-pumped Yb:KGd(WO(4))(2) laser

We report on the laser performance of a diode-pumped Yb:KGd(WO(4))(2) laser that is passively Q switched with a Cr(4+):YAG saturable absorber. Raman conversion of fundamental laser emission in the laser crystal was demonstrated. Q-switched 3.4-mu;J pulses with a pulse width of 85 ns were obtained at the 1033-nm fundamental wavelength and 0.4-mu;J pulses with a pulse width of 20 ns were produced in a first Stokes at 1139 nm.     

Efficient passively Q-switched laser operation of Yb in the disordered NaGd(WO4)2 crystal host

Efficient passively Q-switched laser operation of the disordered Yb:NaGd(WO(4))(2) crystal is demonstrated for the first time to our knowledge with a Cr(4+):YAG saturable absorber by diode end pumping. 2.05 W of average output power at a pulse repetition frequency of 13.3 kHz was obtained at an absorbed pump power of 7.7 W, with a slope efficiency of 40%. The energy and duration of the generated laser pulse were 154 microJ and 33 ns, respectively, corresponding to a peak power of 4.67 kW. In continuous-wave operation, the Yb:NaGd(WO(4))(2) laser yielded an output power of 5.5 W with an optical-optical efficiency of 51%.     

Enhanced efficiency of Er:Yb:Ce:NaGd(WO4)2 laser at 1.5-1.6 microm by the introduction of high-doping Ce3+ ions

By the introduction of high-doping Ce3+ ions, the upconversion fluorescence of Er3+ ions was reduced, and the energy-transfer efficiency from Yb3+ to Er3+ ions was enhanced significantly in Er:Yb:Ce:NaGd(WO4)2 crystals. End pumped by a diode laser at 970 nm in a hemispherical cavity, a 2.0 W quasi-cw laser at 1.5-1.6 microm with slope efficiency of 19% and absorbed pump threshold of 2.0 W was achieved in a 1.7-mm-thick c-cut Er:Yb:Ce:NaGd(WO4)2 crystal. The results show that the Er.:Yb:Ce:NaGd(WO4)2 crystal with high-doping Ce3+ ions is a potential gain medium for a low-threshold 1.5-1.6 microm laser.     

Pulsed laser operation of Y b-dope d KY(WO(4))(2) and KGd(WO(4))(2)

Spectroscopic properties and laser performance of Y b-doped tungstates at pulsed Ti:sapphire laser pumping are reported. Room-temperature lasing near 1025nm is demonstrated in Yb:KY(WO(4))(2) and Yb:KGd(WO(4))(2), with a slope efficiency as great as 86.9%.     

熔盐法生长Nd:KGW多波长激光晶体结构及光谱性能的研究

采用熔盐法,以K2W2O7为助溶剂,优化了晶体生长的工艺参数,生长出了新型稀土激光晶体Nd∶KGW。采用XRD及X射线荧光分析,确认了所得到的晶体为β Nd∶KGW晶体。通过TG DTA分析和测量,得到了其熔点及相变温度分别为1086℃和1021℃。利用红外光谱和Raman光谱确定了其分子基团的振动归属。通过测量其吸收光谱,该晶体在波长为808nm处有强吸收峰,可以与激光二极管有效地耦合。通过计算,获得了其峰值吸收截面积。测试了该晶体的荧光光谱,所得到的晶体发射波长为1.06μm和1.35μm。     

Passively Q-switched microchip Er, Yb:YAl3(BO3)4 diode-pumped laser

We report, for the first time to our knowledge, a diode-pumped cw and passively Q-switched microchip Er, Yb:YAl(3)(BO(3))(4) laser. A maximal output power of 800 mW at 1602 nm in the cw regime was obtained at an absorbed pump power of 7.7 W. By using Co(2+):MgAl(2)O(4) as a saturable absorber, a TEM(00)-mode Q-switched average output power of 315 mW was demonstrated at 1522 nm, with pulse duration of 5 ns and pulse energy of 5.25 μJ at a repetition rate of 60 kHz.     

Self-sum- and -difference-frequency mixing in GdAl(3)(BO(3))(4):Nd(3+) for generation of tunable ultraviolet and infrared radiation

We exploited Nd(3+) laser emission at 1061.9 nm ((4)F(3/2)?(4)I(11/2) channel) in a self-chi((2)) active GdAl(3)(BO(3))(4):Nd(3+) laser crystal. UV radiation was obtained from a 1.8% yield from self-sum-frequency mixing: 1/pump + 1/1061.9 = 1/UV, during pumping in the Nd(3+) (4)G(5/2)-(2)G(7/2) levels near 588 nm. The UV tunability had a range of 378-382 nm. We have demonstrated, for the first time to our knowledge, generation of coherent IR radiation from a self-difference-frequency mixing laser: 1/pump - 1/1061.9 = 1/IR. We got a 0.5% yield and tunability in the 1305-1365-nm range.     

Direct diode-pumped continuous-wave near-inf rared tunable laser operation of Cr(4+):forsterite and Cr(4+):Ca(2)GeO(4)

Continuous-wave tunable laser operation of direct diode-pumped Cr(4+):Mg(2)SiO(4) (Cr:forsterite) and Cr(4+):Ca(2)GeO(4) (cunyite) crystal were demonstrated. Diode-pumped Cr:forsterite was tunable over the 1236-1300-nm spectral range. The maximum output of 10 mW was measured at 1260 nm for 640 mW of pump power absorbed by the crystal. Diode-pumped laser operation of cunyite was also demonstrated over the 1390-1475-nm range. Free-running 20-mW output was centered at 1410 nm.     

Thin-disk Yb:KLu(WO(4))(2) laser with single-pass pumping

Single-pass pumping of a thin disk consisting of an only 50 microm thick epitaxial layer of 32 at.% Yb-doped KLu(WO(4))(2) grown on a 0.35 mm thick undoped KLu(WO(4))(2) substrate is demonstrated. The thin-disk laser delivered 9 W of continuous wave output power near 1030 nm with a slope efficiency of 77%.     

Mode-locked laser operation of epitaxially grown Yb:Klu(WO4)2 composites

Mode locking based on an epitaxial composite of the monoclinic double tungstate crystal Yb:KLu(WO4)2 is realized. A 100 microm thin Yb:KLu(WO4)2 layer grown on a KLu(WO4)2 substrate is used as an active medium in a laser passively mode locked by a semiconductor saturable absorber. Pulse durations of 114 fs have been achieved for an average power of 31 mW at 1030 nm. Results in the femtosecond and picosecond regimes of the Yb:KLu(WO4)2/KLu(WO4)2 laser are presented. The great potential of Yb-doped tungstate composite structures as active elements for mode-locked laser systems is demonstrated.     

Green Er(3+):YLiF(4) upconversion laser at 551nm with Yb(3+) codoping: a novel pumping scheme

We report room-temperature continuous-wave upconversion laser emission on the green transition (4)S(3/2)?(4)I(15/2) in Er(1%), Yb(3%):YLiF(4) at 551nm. Green laser operation was obtained for titanium-sapphire pump wavelengths continuously tunable between 955 and 974.5nm. Codoping with Yb(3+) resulted in a more efficient excitation of the upper laser level by upconversion processes. The maximum green laser output power was 37mW at an incident titanium-sapphire pump power level of 1580mW at 966nm.     

Diode-pumped passively mode-locked Er,Yb:YAl3(BO3)4 laser at 1.5-1.6 microm

We report the first demonstration to our knowledge of passive mode locking in a diode-pumped Er(3+) and Yb(3+) codoped YAl(3)(BO(3))(4) laser operating in the 1.5-1.6 microm spectral region. Low-loss GaInNAs quantum-well semiconductor saturable absorber mirrors are used for the initiation and stabilization of the ultrashort-pulse generation. Pulses as short as 4.8 ps were generated at 1530 nm with an average output power up to 280 mW for 2 W of absorbed pump power produced by a high-brightness tapered 980 nm laser diode. Passive mode locking has also been demonstrated around 1555 nm with typical average powers of around 100 mW and pulse durations of 5.1 ps.     

1.1 W diode-pumped Er:Yb laser at 1520 nm

Laser oscillation at a wavelength of 1520 nm was obtained in an Er:Yb:YAl(3)(BO(3))(4) crystal end pumped by a 970 nm diode laser. Under the absorbed pump power of 14.6 W, quasi-continuous-wave output powers of 1.1 W with slope efficiency of 13% and 0.8 W with slope efficiency of 11% were achieved in hemispherical and plano-plano cavities, respectively. The laser spectra were recorded for both cavities. The influence of the thermal load in the crystal on the 1520 nm laser oscillation was analyzed.     

Efficient 1 W continuous-wave diode-pumped Er,Yb:YAl3(BO3)4 laser

We report the spectroscopy and high-power continuous-wave (CW) diode-pumped laser operation of Er:Yb:YAl3(BO3) crystal. Absorption and stimulated emission spectra, emission lifetimes, and efficiency of energy transfer from Yb3+ to Er3+ ions were determined. A CW Er:Yb:YAB laser emitting at 1602, 1555, and 1531 nm with output power as high as 1W and slope efficiency up to 35% was demonstrated.     

Continuous-wave, all-solid-state, intracavity Raman laser

Continuous-wave operation of a diode-pumped solid-state Raman laser at 1176 nm is reported. The intracavity Raman laser, based on a Nd:YAG laser crystal and a KGd(WO4)2 Raman crystal, reached threshold for 4 W of diode input power and gave up to 800 mW of output power at an overall conversion efficiency of 4%.     

Directly diode-pumped Yb:KY(WO(4))(2) regenerative amplifiers

Two Yb(3+) -doped KY(WO(4))(2) regenerative amplifiers, one end pumped by two 1.6-W single-stripe diodes at 940 nm and the other side pumped by one 20-W diode bar at 980 nm, are demonstrated. When the regenerative amplifiers are injected, 40-muJ , 400-fs and 65-muJ , 460-fs pulses at a 1-kHz repetition rate are obtained following compression from the end- and side-pumped amplifiers, respectively.     

Output-coupling-dependent polarization state of a continuous-wave Yb:YCa4O(BO3)3 laser

High-power continuous-wave laser operation was demonstrated with a y-cut Yb:YCa(4)O(BO(3))(3) crystal, showing critical dependence on the output coupler used. Polarized laser oscillation with E||x was obtained at 1085.6 nm by using a coupler of 0.5% transmission, yielding an output power of 7.3 W with an optical-to-optical efficiency of 63%. Higher output couplings (>/=2%) led to polarized oscillation with E||z at laser wavelengths 相似文献   

Diode-pumped femtosecond Yb:KGd(WO(4))(2) laser with 1.1-W average power

We demonstrate what is to our knowledge the first mode-locked Yb:KGd(WO(4))(2) laser. Using a semiconductor saturable-absorber mirror for passive mode locking, we obtain pulses of 176-fs duration with an average power of 1.1 W and a peak power of 64 kW at a center wavelength of 1037 nm. We achieve pulses as short as 112 fs at a lower output power. The laser is based on a standard delta cavity and pumped by two high-brightness laser diodes, making the whole system very simple and compact. Tuning the laser by means of a knife-edge results in mode-locked pulses within a wavelength range from 1032 to 1054 nm. In cw operation, we achieve output powers as high as 1.3 W.     

Diode-pumped Kerr-lens mode-locked Yb:KY(WO(4))(2) laser

A self-starting Kerr-lens mode-locked Yb:KY(WO(4))(2) laser directly end pumped by two 1.6-W diodes is demonstrated for what is to our knowledge the first time. Pulses as short as 71 fs with 120-mW average output power, at a center wavelength of 1057 nm, were obtained at a repetition rate of 110 MHz. A 10-nm tuning range was achieved with longer pulses and higher average output power.     

Effect of Nd~(3 ) Concentration on theLaser Performance of a New Laser Crystal: Nd: NaY(WO_4)_ 2

The transmission and emission spectra of a new crystal, Nd:NaY(WO4)2(Nd:NYW) have been measured. Using a Ti: Sapphire laser as the pump source, the laser performances of Nd: NYW crystals with different concentrations are compared for the first time. The Nd3 concentrations used are 1, 2, 4 and 5 at.-% . The experiments show that 2 at.-% is the optimum concentration. When the incident pump power is 575 mW, the 1. 06 μm output can reach 184 mW, corresponding to an optical to optical efficiency of 32 % . The experimental results show that the work is significant to the further research and praction application of this promising laser crystal.