Diode-pumped Nd:LGS laser emitting at 888 nm

We present what is, to the best of our knowledge, the first diode-pumped Nd:La₃Ga₅SiO₁₄ (Nd:LGS) laser emitting at 888 nm, based on the ⁴ F _3/2-⁴ I _9/2 transition, generally used for a 904 nm emission. The use of a pump module with 16 passes through the crystal allowed the realization of a Nd:LGS thin-disk laser with 1.41 W of continuous wave (cw) output power at 888 nm. Moreover, intracavity second-harmonic generation (SHG) in cw mode has also been demonstrated with a power of 221 mW at 444 nm by using a BiB₃O₆ (BiBO) nonlinear crystal.     

Up to 30 mW of broadly tunable CW green-to-orange light, based on sum-frequency mixing of Cr:forsterite and Nd:YVO4 lasers

Efficient generation of continuous-wave (CW) tunable light in the yellow region is reported. The method is based on sum-frequency mixing of a tunable Cr⁴⁺:forsterite laser with a Nd:YVO₄ laser. A periodically poled lithium niobate crystal was placed intra-cavity in a Nd:YVO₄ laser, and the Cr⁴⁺:forsterite laser was single-passed through the non-linear media. With this setup, it was possible to generate up to 3 mW of yellow light smoothly tunable from 573 to 587 nm. This is the highest output demonstrated to date for a tunable diode pumped solid-state CW laser in this wavelength region. The ways to improve the efficiency further are discussed.     

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.     

Characteristics of the temperature-tunable Nd:YAG/YVO4 Raman laser

We demonstrate a tunable crystalline Raman laser by varying the temperature of Raman crystal. Nd:YAG and YVO(4) crystals were selected as the laser and Raman gain media, respectively. The center wavelength of this Nd:YAG/YVO(4) Raman laser was tuned over a 0.49 nm range from 1175.76 to 1175.27 nm when the temperature of the Raman crystal was adjusted from 5 °C to 150 °C. The characteristics of this Raman laser including tunability, output power, and beam quality factors (M(2)) dependent on temperature were also studied in this paper.     

LBO Ⅰ类临界相位匹配内腔和频555 nm激光器

报道了全固态连续波555 nm激光器.555 nm激光是分别由Nd:YAG和Nd:YVO4晶体的946 nm和1342 nm谱线非线性和频产生,两条谱线在各自晶体对应能级跃迁分别为4F3/2-4Ⅰ9/2和4F3/2-4Ⅰ13/2.实验中采用复合折叠腔结构,利用LBOI类临界相位进行腔内和频,当注入Nd:YAG和Nd:YVO4晶体的泵浦功率分别为20 W和10 W时,获得1.06 W的TEM00连续波555 nm激光输出.4小时功率稳定度优于±3.3%.实验结果表明采用两种激光晶体进行腔内和频是获得激光的高效方法,并可以应用到其它两种激光晶体进行腔内非线性和频,获得更多不同波长激光输出.     

Picosecond Self-modelocked Wavelength Tunable Ti:Al_2O_3 Laser

1.IntroductionTi:Alzoscrystalasabroadtunablesolid--statelasermaterialbasedonvibronicallybroadenedtransitionsinmetalions,hasseenaresurgenceofresearchanddevelopmentrecently.TheadvantagesofTi:A12O3crystalincludebroadabsorptionandemissionspectrumbandwidth,highbeamqualityandcapabilityofallsolid--stateoperation.KerrlensmodelockedTi:sapphirelaserspumpedbyCWargon--ionlasersarewidelyusedasasourceoffemtosecondopticalpulsesll~'j.KerrlensmodelockingutlizestheorstiealKerreffecttoproduceafastpulse--shor…     

Nd:YAG Lasers Operating at 1064nm and 946nm by Direct Pumping and Thermally Boosted Pumping

We demonstrate a 1064nm Nd：YAG laser by directly pumping into the upper lasing level with a tunable Ti：sapphire laser. The valid wavelength is demonstrated at 868.3nm, 875.2nm, 883.8nm, and 885.5nm, respectively. To our knowledge, this is the first time that 1064nm Nd：YAG laser pumped by 875.2nm laser. In addition, laser wavelength at 946 nm is also generated by direct pumping together with traditional pumping.     

染料激光泵浦Nd：S－VAP晶体激光特性研究

实验测定了Ｎｄ：Ｓｒ５（ＶＯ４）３Ｆ（简称Ｎｄ：Ｓ－ＶＡＰ）晶体的吸收光谱特性；在５８３．０ｎｍ和８０９．０ｎｍ处有强的吸收峰。用可调谐染料激光作泵浦源，实现了低阈值、高效率的激光运转。在透射率１５％的平面平行腔情况下，斜率效率为５０％，阈值为２ｍＪ。倍频光中心波长为５３６．０ｎｍ，线宽为１．４ｍｍ。本文还对Ｎｄ：Ｓ－ＶＡＰ晶体可作为ＬＤ泵浦的小型激光器的工作物质等问题进行了讨论。     

Tunable sub-100 femtosecond dye-laser pulses generated with a nanosecond pulsed pumping

Subpicosecond pulses at a fixed wavelength produced with a low-Q cavity dye laser pumped by a single, nanosecond laser (Q-switched Nd:YAG) are converted into tunable high-power sub-100 femtosecond pulses by generation, spectral selection, amplification and compression of a supercontinuum. The tunable, chirped, high-energy pulses obtained are compressed with a prism pair. Energies up to 50 J in sub-100 fs pulses were obtained in the 540 to 650 nm range using 40 mJ of the Nd: YAG-laser pumping pulses at 532 nm. The whole sub-100 fs system including the low-Q dye laser uses only one Nd:YAG laser as a pump source.     

Temperature-tuned difference-frequency mixing in periodically poled KTiOPO4

4 (PPKTP). We generated 12 μW of radiation tunable around 1.6 μm by difference-frequency mixing of the outputs of a frequency-doubled Nd:YLF laser at 523 nm (240 mW) and a tunable Ti:sapphire laser near 760 nm (340 mW). A temperature tuning rate of 0.73 nm/°C for the generated wavelength and a FWHM temperature acceptance bandwidth of 6.9 °C cm was observed. The effective d₃₃ coefficient was estimated to be ∼5 pm/V. Received: 02 September 1998     

Generation of 520 mW pulsed blue light by frequency doubling of an all-fiberized 978 nm Yb-doped fiber laser source

Pulsed blue light at 489 nm has been generated by second-harmonic-generation of a nanosecond pulsed master-oscillator power amplifier system based on a short Yb(3+) doped single-mode fiber amplifier at 978 nm and an external-cavity diode laser as seed source. The Yb(3+)-doped fiber was core-pumped by a W type Nd(3+) doped double-clad fiber laser operating on the transition near 930 nm ((4)F(3/2)→(4)I(9/2)). 520 mW of average power was generated at 489 nm using a periodically poled MgO:LiNbO(3), corresponding to a conversion efficiency of 34%.     

激光二极管端面抽运Nd:YVO4实现1386 nm连续波激光输出

在Nd:YVO4晶体的4F3/2-4I13/2跃迁带内,除了1342 nm激光辐射之外,其它的跃迁谱线由于小的受激发射截面和强的寄生振荡,很难形成激光振荡.通过调整谐振腔损耗,获得了光纤耦合激光二极管端面抽运1386 nmNd:YVO4激光器激光连续输出.在抽运功率达到4.24 W时,得到了305 mW的1386 nm激光连续输出,最高输出功率下的斜效率为13.9%.实验中还观察到了1342 nm和1386 nm的双波长运转.根据抽运阈值能量和实验数据,计算得到了Nd:YVO4晶体中1386 nm激光辐射处的受激发射截面大约为(3±1)×10-19cm2.     

向列相液晶染料可调谐激光器的研究

对向列相液晶染料的可调谐激光器进行了光学特性研究. 以650 nm为中 心波长设计了SiO₂和TiO₂多层膜的一维光子晶体, 以激光染料与向列相液晶的混合物作为增益介质层, 制备了波长可调谐激光器.用Nd: YAG倍频脉冲激光器输出的532 nm激光抽运所制备的激光器样品得出如下光学特性: 激光发射波长随温度调谐范围为605.5---639.8 nm, 达到34.3 nm, 随电压调谐范围为634.5---619.5 nm, 达到15 nm. 发射激光每脉冲的阈值能量为12.3 μJ, 激光线宽小于1 nm.     

Spectroscopic characterization and laser performance of resonantly diode-pumped Er(3+)-doped disordered NaY(WO4)2

We report what is believed to be the first resonantly pumped laser operation based on Er(3+)-doped disordered double tungstate single crystal. Efficient laser operation of an Er(3+):NaY(WO(4))(2) laser at ～1609.6 nm was demonstrated with the naturally wideband, ～20 nm, InGaAsP/InP laser diode pumping at ～1501 nm. Laser wavelength tunability of ～34 nm was also demonstrated based on disorder-broadened emission features of Er(3+):NaY(WO(4))(2) single crystal.     

Efficient generation of tunable VUV laser radiation below 205 nm by SFM in BBO

Design and performance characteristics of a tunable dye laser system for sum frequency mixing (SFM) in a BBO crystal are presented. The system is composed of two tunable pulsed dye lasers pumped synchronously by the second harmonic of a commercial Nd:YAG laser. The radiation produced by the first dye laser is frequency doubled by second-harmonic generation (SHG) in KDP and subsequently mixed by SFM in BBO with the light of the second dye laser. The interest was focussed on generation of tunable laser radiation below 205 nm with high output power and long-time wavelength stability. High conversion efficiencies enable output energies of 100 J (20 kW) at 196 nm using only moderate Nd:YAG pump energies of 67 mJ. Altogether, a laser system with very good specifications for analytical application in the near VUV spectral region is reported.     

新型晶体Nd:S-VAP激光特性研究

测量了 Nd:S-VAP[Nd:Sr₅(VO₄)₃F]晶体的吸收光谱特性,在583.0nm 和809.0nm处有强烈的吸收峰.用可调谐染料激光泵浦实现了低阈值、高效率的激光运转.在透射率15%的平-平腔情况下,斜率效率为50%,阈值2mJ,倍频绿光的中心波长为536.0nm,线宽为1.4nm.采用φ4mm×30mm 的氙灯泵浦,实现了自由运转和染料片调 Q 运转.阈值为130mJ,斜效率为1.3%.测量了不同腔长、不同染料片小信号透射率情况下的输出能量、脉冲宽度以及光束发散角和偏振特性等.     

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.     

Simultaneous dual-wavelength laser operation at 1342 and 946 nm in two laser crystals and their sum-frequency mixing

A sum-frequency yellow-green laser at 554.9 nm is reported by this paper, 946 nm wavelength is obtained from ⁴F_3/2-⁴I_9/2 transition in Nd:YAG and 1342 nm wavelength is obtained from ⁴F_3/2-⁴I_13/2 transition in Nd:YVO₄. Using a doubly folded-cavity type-II critical phase matching KTP crystal intra cavity to make 946 nm laser from Nd:YAG and 1342 nm laser from Nd:YVO₄ frequency summed, with incident pumped power of 30 W in Nd:YAG and 20 W in Nd:YVO₄, TEM₀₀ mode yellow-green laser at 554.9 nm at 1.15 W is obtained and its M² factor is less than 1.22. The experimental results show that the Nd:YAG and Nd:YVO₄ crystals intra-cavity sum-frequency mixing is an effective method for yellow-green laser and it can be applied to other two laser crystals to obtain more all-solid-state lasers with different wavelengths.     

Passive synchronization of two independent laser oscillators with a Fabry-Perot modulator

By optical modulation of the reflectivity of an intracavity nonlinear Fabry-Perot semiconductor mirror, the pulse train from a passively mode-locked picosecond Nd:YVO(4) laser oscillator is synchronized to an independent femtosecond-mode-locked Ti:sapphire laser. We obtain stable synchronized pulse trains at central wavelengths of 1064 and 850 nm, and the Ti:sapphire laser is still independently tunable over a large wavelength range. The tolerable cavity-length difference between the two laser oscillators exceeds 20mu;m .     

Amplification of spontaneous emission in Nd~(3 )-doped fiber pumped by Ti: Al_2O_3 tunable laser

Amplification of spontaneous emission(ASE) in 4m Nd~(3 )-doped fiber pumped by Ti : Al~2O_3 tunable laser is studied theoretically and experimentally. The output of 2.64mW from ASE source pumped at 833 nm is obtained and the experimental results of ASE source are compared with that of Nd~(3 )-doped fiber ring laser.