Highly efficient continuous-wave intracavity frequency-doubled Nd:YVO4-LBO laser at 457 nm under diode pumping into the emitting level 4F3/2

The continuous-wave high efficiency laser emission of Nd:YVO₄ at the fundamental wavelength of 914 nm and its 457 nm second harmonic obtained by intracavity frequency doubling with an LBO nonlinear crystal is investigated under pumping by diode laser at 880 nm into emitting level ⁴F_3/2. 6.5 W at 457 nm with M ²=1.8 was obtained from a 5-mm-thick 0.4 at.% Nd:YVO₄ laser medium and a 15-mm-long LBO nonlinear crystal in a Z-type cavity for 18.6 W absorbed pump power. An optical-to-optical efficiency with respect to the absorbed pump power was 0.35. Comparative results obtained for the pump with diode laser at 808 nm, into the highly-absorbing level ⁴F_5/2, are given in order to prove the advantages of the 880 nm wavelength pumping.     

500.5-nm blue-green laser based on sum-frequency mixing of diode pumped neodymium lasers

We report for the first time a continuous-wave (CW) coherent radiation at 500.5 nm by intracavity sum-frequency generation of 1063 nm Nd:GdVO₄ laser and 946 nm Nd:YAG laser. Blue-green laser is obtained by using a doubly cavity, type-II critical phase matching KTiOPO₄ (KTP) crystal sum-frequency mixing. With total pump power of 27.8 W, TEM₀₀ mode blue-green laser at 500.5 nm of 421 mW is obtained. At the output power level of 421 mW, the blue-green power stability is better than 2.8% and laser beam quality M ² factor is 1.37.     

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.     

High-efficiency resonantly pumped room temperature Ho:YVO4 laser

An efficient 2 μm room temperature Ho:YVO(4) laser resonantly pumped by a 1.94 μm Tm:YAP laser is demonstrated, for the first time to our knowledge, in this Letter. Up to 8.58 W of laser output at 2053 nm is obtained with the optical-to-optical conversion efficiency as much as 41.2%. The output beam had quality of M² factor with Mx(2) of 3.58 and My(2) of 1.76 at 8 W output level. In addition, we also obtained 4.18 W laser output at 2066 nm and 7.04 W at 2040 nm from the Ho:YVO(4) laser with conversion efficiency of 27.8% and 33.8%, respectively.     

电泳式He-Sr+复合激光特性研究

设计制作了7mm内径和38cm有效激励长度的电泳式He-Sr⁺激光管,采用修饰Blumlein电路,通过纵向高重复率脉冲放电激励,实现了一价锶离子复合激光430.5nm和R-M跃迁激光1.03μm的同时振荡,其中复合激光占主要成分.测量分析了复合激光输出功率与工作参量(脉冲频率,充电电源电压和氦压)的关系曲线.获得了最大激光功率819mW和56mW/cm³功率密度的实验结果. 关键词： 锶离子激光 电泳 脉冲放电     

Diode-pumped Nd:YCOB self-frequency-doubling green laser at 530 nm

It is reported that efficient continuous-wave (CW) self-frequency-doubling green laser at 530 nm performed with a diode-pumped Nd³⁺:YCa₄O(BO₃)₃ (Nd:YCOB) laser. With a diode pump power of 14.3 W, TEM₀₀ mode green laser at 530 nm of 1.07 W is obtained. At the output power level of 1.07 mW, the output stability is better than 5%. The beam quality M² value is about 1.37. To the best of our knowledge, this is the highest power laser at 530 nm generated by self-frequency doubling of a diode pumped Nd:YCOB laser.     

Diode-pumped Nd:YCOB self-frequency-doubling red laser at 666 nm

It is reported that efficient continuous-wave (CW) self-frequency-doubling red laser at 666 nm performed with a diode-pumped Nd³⁺:YCa₄O(BO₃)₃ (Nd:YCOB) laser. With a diode pump power of 14.3 W, TEM₀₀ mode red laser at 666 nm of 570 mW is obtained. At the output power level of 570 mW, the output stability is better than 3.5%. The beam quality M² value is about 1.25. To the best of our knowledge, this is the highest power laser at 666 nm generated by self-frequency doubling of a diode pumped Nd:YCOB laser.     

480-nm blue laser based on sum-frequency mixing of diode pumped Nd:ASL-Yb:YAG lasers

We report for the first time a continuous-wave (CW) coherent radiation at 480 nm by intracavity sum-frequency generation of 900 nm Neodymium Doped Strontium and Lanthanum Aluminate (Nd:ASL) laser and 1030 nm Yb:Y₃Al₅O₁₂ (Yb:YAG) laser. Blue laser is obtained by using a doubly cavity, type-I critical phase matching LiB₃O₅ (LBO) crystal sum-frequency mixing. With total pump power of 28.6 W, the blue laser at 480 nm of 170 mW is obtained. At the output power level of 170 mW, the blue power stability is better than 4.7% and laser beam quality M ² factor is 1.43.     

Atomic nitrogen laser action in a hollow cathode discharge

Near-infrared laser action of nitrogen atoms was obtained in a hollow cathode discharge. Four laser lines at wavelengths of 1358.2, 939.3, 938.7, and 862.9 nm were observed in the cw mode. In addition, the laser line at 904.6 nm was observed in quasi-cw operation in the afterglow for the first time. It is supposed that resonant charge exchange between He⁺ and N₂ followed by predissociation of N ₂ ⁺ is an important way of populating the upper laser levels.     

All solid-state continuous-wave intracavity frequency-doubled Nd:LuVO<Subscript>4</Subscript>-LBO red laser at 671.5 nm

We report for the first time a efficient compact red laser at 671.5 nm generation by intracavity frequency doubling of a continuous wave laser operation of a diode direct pumped Nd:LuVO₄ laser on the ⁴ F _3/2 → ⁴ I _13/2 transition at 1343 nm. An LBO crystal, cut for critical type I phase matching at room temperature is used for second harmonic generation of the laser. At an absorbed pump power of 16.2 W, as high as 4.3 W of continuous wave output power at 671.5 nm is achieved with 10-mm-long LBO. Comparative results obtained for the pump with diode laser at 808 nm, into the highly-absorbing ⁴ F _5/2 level, are given in order to prove the advantages of the 880 nm wavelength pumping.     

504 nm blue-green laser based on sum-frequency mixing of diode pumped Nd<Superscript>3+</Superscript> lasers

We report for the first time a continuous-wave (CW) blue-green radiation at 504 nm by intracavity sum-frequency generation of 946 nm Nd:YAG laser and 1080 nm Nd:YAlO₃ (Nd:YAP) laser. Using type-I critical phase matching LiB₃O₅ (LBO) crystal, 504 nm blue-green laser was obtained by 946 and 1080 nm intra-cavity sum-frequency mixing, and output power of 215 mW was demonstrated. At the output power level of 215 mW, the output power stability is better than 4.7% and laser beam quality M² factor is 1.21.     

高功率光子晶体光纤激光器实验研究

 利用F-P谐振腔实验研究了高功率掺Yb³⁺光子晶体光纤激光器。使用915 nm和976 nm两种波长的泵浦源进行双端泵浦,在23 m长的双包层光子晶体光纤中获得了552 W的连续单模激光输出。该激光器的斜率效率约为76%,光-光转换效率为56%,光谱中心波长为1 078 nm,光束质量平方因子为1.2。     

Spectroscopy of Te2 with modulation transfer: Reference lines for precision spectroscopy in Yb+ at 467 nm

Modulation-transfer spectroscopy is used to observe resonances in ¹³⁰Te₂ near 467 nm. A signal-to-noise ratio of 500 is obtained with 1 mW laser power and with a time constant of 10 ms; the lineshapes are investigated in detail for different demodulation phases. The signal can be used to servolock a blue dye ring laser at 467 nm on a ¹³⁰Te₂ resonance which serves as reference line for precision spectroscopy on single, trapped Yb⁺ ions at 467 nm.     

Diode-Pumped Nd:CNGG-LBO CW sum-frequency mixing blue-green laser at 497 nm

We report for the first time a continuous-wave (CW) blue-green laser emission by sum-frequency mixing in Nd:CNGG crystal. Using type-I critical phase-matching LBO crystal, a blue-green laser at 497 nm is obtained by 1061 and 935 nm intracavity sum-frequency mixing. The maximum laser output power of 232 mW is obtained when an incident pump laser of 18.2 W is used. At the output power level of 232 mW, the output stability is better than 3.67%. The beam quality M ² value is are about 1.26 and 1.38 in both horizontal and vertical dimensions respectively.     

Highly efficient Nd:GdVO4/BiBO laser at 456 nm under direct 880 nm diode laser pumping

The continuous-wave high-efficiency laser emission of Nd:GdVO₄ at the second-harmonic of 456 nm obtained by intracavity frequency doubling with an BiB₃O₆(BiBO) nonlinear crystal is investigated under pumping by diode laser at 880 nm into emitting level ⁴F_3/2. About 3.8 W at 456 nm with M² = 1.4 was obtained from a 5 mm-thick 0.4 at.% Nd:GdVO₄ laser medium and a 12 mm-long BiBO nonlinear crystal in a Z-type cavity for 13.9 W absorbed pump power. An optical-to-optical efficiency with respect to the absorbed pump power was 0.274. Comparative results obtained for the pump with diode laser at 808 nm, into the highly-absorbing ⁴F_5/2 level, are given in order to prove the advantages of the 880 nm wavelength pumping.     

All solid-state continuous-wave Nd:YAG laser at 1319 and 659.5 nm under direct 885 nm pumping

The continuous-wave high efficiency laser emission of Nd:YAG at the fundamental wavelength of 1319 nm and its 659.5-nm second harmonic obtained by intracavity frequency doubling with an LBO nonlinear crystal is investigated under pumping by diode laser at 885 nm (on the ⁴ F _3/2 → ⁴ I _13/2 transition). An end-pumped Nd:YAG crystal yielded 9.1 W at 1319 nm of continuous-wave output power for 18.2 W of absorbed pump power. The slope efficiency with respect to the absorbed pump power is 0.55. Furthermore, 5.2 W 659.5 nm red light is acquired by frequency doubling, resulting in an optical-to-optical efficiency with respect to the absorbed pump power of 0.286. Comparative results obtained for the pump with diode laser at 808 nm (on the ⁴ F _5/2 → ⁴ I _13/2 transition) are given in order to prove the advantages of the 885 nm wavelength pumping.     

Diode-side-pumped Nd:GGG laser at 1,105?nm and frequency-doubled laser at 552?nm

A high-power diode-side-pumped 1,105?nm Nd:GGG laser and a laser at 552?nm based on intracavity frequency doubling of 1,105?nm laser are demonstrated for the first time. A 26.8-W 1,105?nm laser continuous wave output was achieved under the incident pump power of 170?W. A LiB₃O₅ crystal is used for second harmonic generation of 1,105?nm laser. When the pump power was 170?W, the average output power at 552?nm of 7.3?W was obtained, corresponding to the optical conversion efficiency of 4.3?%. And the minimum pulse width is 181?ns with the pulse repetition rate of 10?kHz. The M ² factors are measured to be 19.8 and 17.6 in the horizontal and vertical directions, respectively.     

Highly efficient intracavity frequency-doubled Nd:GdVO4-LBO red laser at 670 nm under direct 880 nm pumping

We report the efficient compact red laser at 670 nm generation by intracavity frequency doubling of a continuous wave laser operation of a diode direct pumped Nd:GdVO₄ laser on the ⁴ F _3/2 → ⁴ I _13/2 transition at 1340 nm. An LBO crystal, cut for critical type I phase matching at room temperature is used for second harmonic generation of the laser. At an absorbed pump power of 16.2 W, as high as 5.1 W of continuous wave output power at 670 nm is achieved with 15-mm-long LBO. The optical-to-optical conversion efficiency is up to 0.31, and the fluctuation of the red output power was better than 3.0% in the given 30 min. Comparative results obtained for the pump with diode laser at 808 nm, into the highly-absorbing ⁴ F _5/2 level, are given in order to prove the advantages of the 880 nm wavelength pumping.     

Tunable single-mode pulsed Ti3+:Sapphire laser injection-seeded by a continuous-wave Cr3+:LiSrAlF6 laser

Spectrally pure high-power tunable single-mode operation of a pulsed Ti³⁺:sapphire laser by a tunable injection-seeding is reported. The injection laser was a cw diode laser pumped, spectrally narrowed tunable Cr³⁺:LiSrAlF₆ (Cr³⁺:LiSAF) laser with a grating in the auxiliary cavity. Single-mode tunable operation of a pulsed Ti³⁺: sapphire ring oscillator was obtained at different wavelengths in the range between 818 nm and 848 nm with a typical linewidth of 0.006 cm^-1. To extend the applicability of this operation to a differential absorption lidar system, the single-mode Ti³⁺:sapphire oscillator output was amplified and a high energy output of 38 mJ was obtained with the same linewidth.     

A 7.5?W quasi-continuous-wave sodium D2 laser generated from?single-pass sum-frequency generation in LBO crystal

We report a high-power, narrow linewidth and tunable quasi-continuous-wave (QCW) yellow laser system at 589.159?nm. The system is of a design employing single-pass sum-frequency generation (SFG) in a LBO crystal by mixing the 1064?nm with 1319?nm lines from a two diode-side-pumped Nd:YAG master oscillator-power amplifier (MOPA) laser system. With the pump power of 35?W at 1064?nm and 25?W at 1319?nm, a 7.5?W QCW output of the SFG yellow laser at 589.159?nm, which is the vacuum wavelength of a general sodium D₂ line, is obtained with a linewidth less than 0.7?GHz and a beam-quality factor M ²=1.2. The wavelength of the laser can be precisely step-tuned from 589.148 to 589.167?nm with an increment of 0.13?pm by means of a temperature-controlled etalon.