LD侧泵Nd∶YAG/S-KTP腔内倍频高功率660nm连续红光激光器

报道了LD侧面泵浦Nd∶YAG/S-KTP腔内倍频高功率660nm连续红光激光器。泵浦组件（呈三角形等间距分布）由9个20W的激光二极管组成，最大泵浦功率为180W。通过对谐振腔参数进行优化设计，用LD连续抽运3mm×65mm Nd∶YAG激光棒时，获得了波长为1319nm的基频光振荡。利用S-KTP II类临界相位匹配腔内倍频技术，当泵浦电流为22A时，获得了6.8W的连续红光激光输出，光-光转换效率为4.3％。     

Compact, efficient diode-end-pumped Nd:GdVO4 slab continuous-wave 912-nm laser

A fiber-coupled laser-diode (LD) end-pumped Nd:GdVO₄ slab continuous-wave (CW) 912-nm laser and an LD bar end-pumped Nd:GdVO₄ slab CW 912-nm laser are both demonstrated in this paper. Using the fiber-coupled LD of end-pumped type, a highest CW 912-nm laser output power of 10.17 W is obtained with a high optical-to-optical conversion efficiency of 24.6% and a slope efficiency of 34.5%. The measured M² factors of beam quality in x and y directions are 5.3 and 5.1, respectively. Besides, an LD bar of end-pumped type is used to realize CW 912-nm laser output, which has the advantages of compactness and low cost. When the pump power is 38.8 W, the output power is 8.87 W and the measured M² factors of beam quality in x and y directions are 16 and 1.31, respectively. In order to improve the beam quality of the 912-nm laser at x direction, a new quasi-concentric laser resonator will be designed, and an LD bar end-pumped Nd:GdVO₄ slab high-power CW 912-nm TEM₀₀ laser will be realized in the future.     

激光二极管泵浦Nd：YVO4／LBO腔内倍频瓦级连续波绿光激光器

报道一种激光二极管端面泵浦ＮｄＹＶＯ４晶体、ＬＢＯ腔内倍频的全固态瓦级连续波（ＣＷ）绿光激光器。对ＬＢＯ采用Ｉ类非临界相位匹配（ＮＣＰＭ）、温度调谐，当泵光功率为５．５Ｗ时，获得了１．２ＷＴＥＭ００模５３２ｎｍ连续波绿光输出，光－光转换效率达２２％，电－光转换效率达３％。     

High beam quality and compact diode end-pumped Nd:YVO<Subscript>4</Subscript> slab laser with a hybrid resonator

A compact, high power and high beam quality diode-end-pumped CW Nd:YVO₄ slab 1064 nm laser with a hybrid resonator is demonstrated. The maximum output power of 23.0 W is obtained under the pump power of 66.7 W, which gives the slope efficiency and optical conversion efficiency of 52.0 and 34.0%, respectively. The beam quality M² factors are measured to be 1.5 in the unstable direction and 1.7 in the stable direction. The power stability of the LD end-pumped slab laser at an output power of 19 W is measured to be 0.7% for half an hour operation.     

High power and efficiency of a 2044-nm c-cut Tm, Ho:YAlO3 laser

A high power and efficiency of c-cut Tm, Ho:YAlO₃ (YAP) laser is reported in the paper. The laser operated in continuous wave (CW) mode or Acousto-optical (AO) Q-switched mode at 2044 nm. The Tm, Ho:YAP crystal was cooled at the temperature of 77 K and pumped by a fiber-coupled laser diode (LD) with the centre output wavelength of 794.8 nm. In CW operation, a 9.30-W output power was obtained at a 150-mm physical cavity length, corresponding to a slope efficiency of 42.5%. In Q-switch mode, the output average power of 9 W was achieved at the pulse repetition frequency (PRF) of 10 kHz with a 130-ns pulse width. Moreover, the energy per pulse of 3.54 mJ in 47 ns was acquired at 2.5 kHz with a 75.3-kW peak power.     

High power 1341.4 nmNd:YAlO3 CW laser and its performances

A lamp pumped high power 1341.4 nmNd:YAlO₃CW laser and its performances have been described. As high as 188 W of CW output power has been obtained at 1341.4 nm alone line with a overall efficiency of 1.37% and a slope efficiency of 2.14%. The divergence (FWHM) and instability (RMS) of this laser at output power of 155 W are 15 mrad and 1.19%, respectively.     

All-fiber clad-pumped Tm3+-doped fiber amplifier using high power fiber combiner

The diode laser (LD) clad-pumped 1947.6 nm continuous wave (CW) Tm³⁺-doped fiber amplifier is reported using the master oscillation power amplifier (MOPA) method. The injected seed laser is provided by an all-fiber LD-clad-pumped Tm³⁺-doped single-mode fiber laser, which has a nearly 2.4 W maximal output power and 0.1 nm ultra-narrow linewidth based on the intracore reflection FBG. Using the 25/400 μm double-clad LMA Tm³⁺-doped fiber as the gain fiber, the output maximal output power is 30.6 W from the fiber amplifier, with a slope efficiency of 39.1% respected to the LD total output power. A high power multi-mode fiber combiner is used to couple high power LD light into the gain fiber. The output wavelength is also located at 1947.6 nm, with the slightly expanded laser linewidth of 0.2 nm.     

Efficient Nd:YVO_4 laser in-band pumped by wavelength-locked 913.9-nm laser diode and Q-switch operation

An efficient 1064-nm Nd:YVO_4laser in-band pumped by a wavelength-locked laser diode(LD) at 913.9 nm was demonstrated. The maximum continuous wave(CW) output power of 23.4 W at 1064 nm was realized with the incident pump power of 40 W, corresponding to a total optical-to-optical efficiency of 58.5%. This is to the best of our knowledge the highest total optical-to-optical efficiency and output power of Nd:YVO_4laser in-band pumped by a 913.9-nm laser diode.The Q-switched operation of this laser was also investigated. Through a contrast experiment of pumping at 808 nm, the experimental results showed that an Nd:YVO_4laser in-band pumped by a wavelength-locked LD at 913.9 nm had excellent pulse stability and beam quality for high repetition rate Q-switching operation.     

NdKYW新型全固体激光器研究

报道了采用半导体二极管抽运的掺钕钨酸钇钾［Nd3+KY(WO4)2］(简称NdKYW)蓝绿光激光器。腔内倍频采用了Ⅰ类临界相位匹配LBO(LiB3O5)晶体作为倍频器,阈值抽运功率为400 mW,在抽运功率为2 W时获得了200 mW的530 nm连续激光输出,其倍频光的光-光转换效率为10%。     

LD end-pumped passively mode-locked Nd:YVO<Subscript>4</Subscript> laser with single-walled carbon nanotubes

We demonstrate a LD end-pumped passively mode-locked Nd:YVO₄ laser using a single-walled carbon nanotubes saturable absorber (SWCNT-SA). The SWCNT wafer was fabricated by electric arc discharge method on quartz substrate with absorption wavelength of 1064 nm. At the absorbed pump of 15.8 W, an output power of 750 mW CW (continuous wave) mode-locked laser pulse was achieved with the repetition of 79.7 MHz, corresponding to optical-optical efficiency of 4.75%.     

All-solid-state continuous-wave frequency doubling Nd:LuVO4/LBO laser with 9.6 W output power at 672 nm

An efficient and compact red laser at 672 nm is generated by intracavity frequency doubling of a continuous wave (CW) laser operation of a diode pumped Nd:LuVO₄ laser at 1344 nm under the condition of suppression the higher gain transition near 1064 nm. With 38 W diode pump power and a frequency doubling crystal LBO, as high as 9.6 W of CW output power at 672 nm is achieved, corresponding to an optical-to-optical conversion efficiency of 25.3% and the output power stability in 8 h is better than 2.38%. To the best of our knowledge, this it the highest conversion efficiency of watt-level laser at 672 nm generated by intracavity frequency doubling of a diode pumped Nd:LuVO₄ laser at 1344 nm.     

All-solid-state CW frequency-doubling Nd:LuVO<Subscript>4</Subscript>/KTP laser with 2.3 W output power at 545 nm

Efficient and compact green-yellow laser output at 545 nm is generated by intracavity frequency doubling of a continuous-wave (CW) diode-pumped Nd:LuVO₄ laser at 1089 nm under the condition of suppressing the higher gain transition near 1066 nm. With 18.7 W of diode pump power and the frequency-doubling crystal KTiOPO₄(KTP), as high as 2.3 W of CW output power at 545 nm is achieved, corresponding to an optical-to-optical conversion efficiency of 12.3%; the output power stability over 4 h is better than 5.4%.     

All-solid-state 543 nm green laser generated by frequency doubling of a diode pumped Nd:YVO<Subscript>4</Subscript> laser at 1086 nm

An efficient and compact green laser at 543 nm is generated by intracavity frequency doubling of a continuous wave (CW) laser operation of a diode pumped Nd:YVO₄ laser at 1086 nm under the condition of suppression the higher gain transition near 1064 nm. With 10 W diode pump power and a frequency doubling crystal LBO, as high as 2.13 W of CW output power at 543 nm is achieved, corresponding to an optical-to-optical conversion efficiency of 21.3% and the output power stability in 3 h is better than 2.27%.     

800 mW/1484 nm highly efficient two-cascaded phosphosilicate Raman fiber laser pumped by Nd:YVO4 solid-state laser

Using 1064 nm CW Nd:YVO₄ solid-state laser as a pump, 1-km phosphosilicate fiber and cascaded cavities with two pairs of fiber Bragg grating mirrors for 1239 and 1484 nm, we obtained a CW 800 mW/1484 nm Raman fiber laser (RFL) for an actual incident pump power of about 2 W (Nd:YVO₄ power of 6.90 W). The conversion efficiency is as high as 40%. To the best of our knowledge, this is the highest conversion efficiency of RFL pumped by solid-state laser. The output power instability at 1484 nm in half an hour is less than 3%. In addition, the numerical simulations are also performed. Good agreement between the results of numerical simulation and the results of the experiment has been demonstrated.     

All-solid-state continuous-wave frequency doubling Nd:LuVO4/LBO laser with 9.6 W output power at 458 nm

An efficient and compact red laser at 458 nm is generated by intracavity frequency doubling of a continuous wave (CW) laser operation of a diode pumped Nd:LuVO₄ laser at 916 nm under the condition of suppression the higher gain transition near 1064 nm. With 30 W diode pump power and a frequency doubling crystal LBO, as high as 9.6 W of CW output power at 458 nm is achieved, corresponding to an optical-to-optical conversion efficiency of 32.0% and the output power stability in 8 hours is better than 2.35%. To the best of our knowledge, this it the highest conversion efficiency of watt-level laser at 458 nm generated by intracavity frequency doubling of a diode pumped Nd:LuVO₄ laser at 916 nm.     

Laser spectrum of a high power Tm,Ho:GdVO<Subscript>4</Subscript> laser

In this paper, we report a 18.8 W continuous wave and 18.4 W Q-switched diode-pumped cryogenic Tm(5 at %), Ho(0.5 at %):GdVO₄ laser. The pumping source of Tm, Ho:GdVO₄ laser is a fiber-coupled laser diode with fiber core diameter of 0.4 mm, supplying 42 W power at 802.5 nm. For input pump power of 41.9 W at 802.4 nm, the output power of 18.8 W in CW operation, optical-to-optical conversion efficiency of 45% at 2.05 μm and the average output power of 18.4 W in Q-switched operation, optical-to-optical conversion efficiency of 44% at 2.04 and 2.05 μm have been attained. The emission wavelengths of the Tm(5 at %), Ho(0.5 at %):GdVO₄ laser were firstly compared when it worked in CW mode and Q-switched mode.     

All-solid-state CW doubly resonant sum-frequency mixing red-orange laser at 611 nm

We report for the first time a continuous wave (CW) coherent radiation at 611 nm by intracavity sum-frequency generation of 1064 nm Nd:YVO₄ laser and 1433 nm Nd:YAP laser. Red-orange laser is obtained by using a doubly cavity, type-II critical phase matching KTP crystal sum-frequency mixing. With total pump power of 27.9 W (17.8 W pump power for 1433 nm Nd:YAP laser and 10.1 W pump power for 1064 nm Nd:YVO₄ laser), TEM₀₀ mode red-orange laser at 611 nm of 1.15 W is obtained. The red-orange power stability in 30 min is better than 4.3%.     

All solid-state CW Nd:LuVO<Subscript>4</Subscript>-LBO yellow-green laser under direct 888 nm pumping

We report a yellow-green laser at 544.5 nm generation by intracavity frequency doubling of a continuous wave (CW) laser operation of a 1089 nm Nd:LuVO₄ laser under in-band diode pumping at 888 nm. An LBO crystal, cut for critical type I phase matching is used for second harmonic generation of the laser. At an incident pump power of 17.9 W, as high as 3.81 W of CW output power at 544.5 nm is achieved. The optical-to-optical conversion efficiency is up to 21.3%, and the fluctuation of the yellow-green output power was better than 3.7% in the given 4 h.     

Diode-pumped laser performance of Tm:Sc_2SiO_5 crystal at 1971 nm

The 4-at.% Tm:Sc_2SiO_5 (Tm:SSO) crystal is successfully obtained by the Czochralski method. The optical properties and thermal conductivity of the crystal are investigated. The broad continuous wave(CW) laser output of(100)-cut Tm:SSO with the dimensions of 3 mm×3 mm×3 mm under laser diode(LD)-pumping is realized. The full width at half maximum(FWHM) of the laser emitting reaches up to 21 nm. The laser threshold of Tm:SSO is measured to be 0.43 W. Efficient diode-pumped CW laser performance of Tm:SSO is demonstrated with a slope efficiency of 25.9% and maximum output power of 934 mW.     

CW Nd:LuVO<Subscript>4</Subscript>-GdCa<Subscript>4</Subscript>O(BO<Subscript>3</Subscript>)<Subscript>3</Subscript> red laser under direct 888 nm pumping

We report a red laser at 672 nm generation by intracavity frequency doubling of a continuous wave (CW) laser operation of a 1343 nm Nd:LuVO₄ laser under in-band diode pumping at 888 nm. An GdCa₄O(BO₃)₃ (GdCOB) crystal, cut for critical type I phase matching at room temperature is used for second harmonic generation of the laser. At an incident pump power of 17.8 W, as high as 1.73 W of CW output power at 672 nm is achieved. The optical-to-optical conversion efficiency is up to 9.7%, and the fluctuation of the red output power was better than 3.3% in the given 30 min.