4.81 W Yb:YAG/1 030 nm薄片激光器优化设计

设计了四程泵浦的Yb:YAG薄片激光器。晶体掺杂原子数分数为10%,几何尺寸为直径10 mm、厚340 μm,提出了Cr/Au金属化方案, 采用铟焊工艺将其焊接到微通道水冷热沉上。耦合系统为四程泵浦结构,球面镜规格为直径30 mm、曲率半径50 mm。利用LightTools软件模拟计算了泵浦光斑半径,选用曲率半径200 mm输出镜以使泵浦光斑半径与基模光斑半径比符合模式匹配原则。在激光二极管阵列泵浦功率为18.73 W 时,获得了最高功率为4.81 W的1 030 nm连续激光输出,光-光转换效率为25.7%。     

Intracavity frequency doubling with a Yb:YAG/LBO laser at 515 nm

We, for the first time, report the intracavity frequency doubling at 1030 nm in an LBO nonlinear optical crystal, at a type-I phase-matching direction of (θ, Φ) = (90°, 13.6°), performed with a double-LD polarization coupled system. With an incident power of 2 W, the maximum output power of 5.62 mW at 515 nm was obtained using a 2 × 2 × 10 mm³ LBO crystal. The threshold was 726 mW. The optical conversion efficiency was 0.28%.     

Continuous-wave and Q-switched performance of an Yb:YAG/YAG composite thin disk ceramic laser pumped with 970-nm laser diode

Using front face-pumped compact active mirror laser （CAMIL） structure, we have demonstrated an Yb：YAG/YAG composite ceramic disk laser with pumping wavelength at 970 nm. The laser has been operated in both continuous-wave （CW） and Q-switching modes. Under CW operation, laser output power of 1.05 W with 2% transmission output coupler was achieved at the wavelength of 1031 nm. Q- switched laser output was gotten by using an acousto-optic Q-switch. The repetition rate ranged from 1 to 30 kHz and the pulse width varied from 166 to 700 ns.     

Laser diode end-pumped Yb:YAG/LBO green laser

With a type-I critical phase-matching LBO crystal, an intracavity frequency doubled solid-stated Yb:YAG green laser is reported. Using a plano-concave resonator, with pump power of 1.37 W, 24.5 mW TEM₀₀ continuous wave laser at 525 nm was obtained. The optical conversion efficiency is 1.8%. By adjusting the placed angle of LBO, several lasers wavelength from 525.0 to 537.8 nm could be extracted. The maximum output power at 537.8 nm is 3.1 mW.     

All-solid-state low noise Yb:YAG/LBO green laser at 515 nm

We report the efficient compact green laser at 515 nm generation by intracavity frequency doubling of a continuous wave (CW) laser operation of a diode-pumped Yb:YAG laser on the transition at 1030 nm. An LBO crystal, cut for critical type I phase matching at room temperature is used for second harmonic generation (SHG) of the laser. With the incident pump power of 10 W, 270 mW of CW output power at 515 nm is achieved with 15-mm-long LBO. The optical-to-optical conversion efficiency is 2.7%, and the power stability in 8 h is better than 2.36% with low noise.     

CW green laser at 520 nm based on sum-frequency mixing of diode pumped Yb:YAG laser

We report for the first time a continuous-wave (CW) green laser emission by sum-frequency mixing in Yb:YAG crystal. Using type-I critical phase-matching LBO crystal, a green laser at 520 nm is obtained by 1030 and 1048 nm intracavity sum-frequency mixing. The maximum laser output power of 269 mW is obtained when an incident pump laser of 17.8 W is used. At the output power level of 269 mW, the output stability is better than 3.2%.     

A passively Q-switched diode pumped Yb:YAG microchip laser

A passively Q-switched diode pumped Yb:YAG microchip laser with Cr4+:YAG saturable absorber mirror is reported. The TEMoo laser pulses are obtained with 1,7-uJ pulse energy, 15-ns pulse width, 0.11-kW peak power, and a repetition rate of 2.2 kHz at 1049 nm. The doped concentration and dimension of Yb:YAG microchip crystal are 10 at.-% and 5×0.6 mm2, respectively.     

Efficient femtosecond Yb:YAG laser pumped by a single-mode laser diode

Single-mode diodes enable a particularly simple, compact and effective pumping of solid-state laser devices for many specialized applications. We investigated a single-mode, 300-mW laser diode for pumping at 935 nm a Yb:YAG laser passively mode-locked by a semiconductor saturable absorber. Relatively short pulse generation (156 fs), tunable across 1033–1059 nm has been demonstrated. An optical-to-optical efficiency of about 28% has been obtained with 320 fs long pulses. Therefore, contrarily to what previously believed, compact diode-pumped ultrafast Yb:YAG oscillators can reliably and efficiently deliver pulses in the range of ≈ 100–200 fs with few tens of mW, which are very appealing for bio-diagnostics and amplifier seeding applications.     

激光二极管泵浦的重复频率大能量低温Yb:YAG激光器设计

为实现重复频率大能量激光输出,基于Yb:YAG激光介质低温下良好的热特性和激光特性,设计了12 kW高功率激光二极管(LD)阵列泵浦的V型腔低温Yb:YAG激光器（液氮温度）。对于泵浦耦合系统和散热结构两个关键点,分别使用光线追迹方法和有限元方法进行了分析,提出了楔形真空窗口和低温热管等解决方案。模拟结果表明,该设计的激光器热效应较低,可实现重复频率大能量输出。     

激光二极管泵浦的重复频率大能量低温Yb:YAG激光器设计

为实现重复频率大能量激光输出,基于Yb:YAG激光介质低温下良好的热特性和激光特性,设计了12kW高功率激光二极管(LD)阵列泵浦的V型腔低温Yb:YAG激光器(液氮温度)。对于泵浦耦合系统和散热结构两个关键点,分别使用光线追迹方法和有限元方法进行了分析,提出了楔形真空窗口和低温热管等解决方案。模拟结果表明,该设计的激光器热效应较低,可实现重复频率大能量输出。     

100-W quasi-continuous-wave diode radially pumped microchip composite Yb:YAG laser

A diode radially pumped microchip Yb:YAG laser that consists of an Yb-doped core surrounded by undoped YAG of a slab shape is presented. Quasi-continuous-wave pumping of a 10-at. % Yb-doped core of 2 mmx2 mm square shape with pulses of 5-Hz repetition rate and 2.5% duty cycle delivers 66-W output peak power at 220-W input pump power with 0.49 slope efficiency. The best results, 112-W peak power with 0.63 slope efficiency and 0.38 optical-to-optical efficiency, were obtained with a 1.2 mmx1.2 mm square 15-at. % at Yb:YAG core.     

Efficient CW Yb:YAG laser at 1048 nm under 968 nm diode laser pumping

We describe the output performances of the 1048 nm transition in Yb:YAG under in-band pumping with diode laser at the 968 nm wavelength. An end-pumped Yb:YAG crystal yielded 787 mW of continuous-wave (CW) output power for 9.1 W of absorbed pump power. Furthermore, 104 mW 524 nm green light was acquired by frequency doubling. Comparative results obtained for the pump with diode laser at 940 nm are given in order to prove the advantages of the in-band pumping.     

Highly efficient CW intracavity frequency-doubled Yb:YAG-LBO laser at 515 nm under 968 nm diode laser pumping

We describe the output performances of the 1030 nm transition in Yb:YAG under in-band pumping with diode laser at the 968 nm wavelength. An end-pumped Yb:YAG crystal yielded 1.93 W of continuous-wave (CW) output power for 9.1 W of absorbed pump power. The slope efficiency with respect to the absorbed pump power was 23.6%. Furthermore, 205 mW 515 nm green light was acquired by frequency doubling, resulting in an optical-to-optical efficiency with respect to the absorbed pump power of 2.7%. Comparative results obtained for the pump with diode laser at 940 nm are given in order to prove the advantages of the in-band pumping.     

Optimizing the Yb:YAG thin disc laser design parameters

Based on quasi-three-level system, a numerical model of continuous wave thin disc laser is proposed. The fluorescence concentration quenching (FCQ), refractive index depending concentration effects and temperature distribution in the gain medium have been taken into account in the model. The first and second phenomena are not included in previously models. The model is used to determine optimum design parameters and to calculate the influence of various parameters like temperature, number of pump beam passes, active ions concentration and the crystal thickness on the operational efficiency of the laser. This model shows that for higher doping concentrations (>15%) the optical efficiency is decreased due to fluorescence concentration quenching. Our results are excellently in agreement with experimental results.     

High power continues wave laser diode array end pumped Nd:YAG/LBO red lasers operated at 669 nm and 659 nm

In this paper, we present using Nd:YAG as the laser media, and Brewster plate as a polarizer device to obtain the linear polarization output at the fundamental wavelength. Using LBO (LiB₃O₅) crystal as non-linear crystal to obtain intra-cavity frequency doubled red laser at 659 and 669 nm and sum frequency mixing at 665 nm. Using a thin fused silica plate as an etalon to obtain the single wavelength operation. At total pump power of 30 W at 808 nm, the output powers at two wavelengths are about 4.1 and 4.5 W, respectively, only one fundamental wavelength light is resonating. The corresponding optical to optical conversion efficiency from pump light to second harmonic generation are 13.7 and 15.0%, respectively.     

Laser diode partially end-pumped electro-optically Q-switched Yb:YAG slab laser

A laser diode partially end-pumped, electro-optically Q-switched, Yb:Y_3Al_5O_(12)(Yb:YAG) slab laser was reported. We obtained output energy of 14.6 mJ/pulse with a pulse width of 30 ns at a repetition frequency of 2 k Hz, and the corresponding peak power was 480 kW. The beam quality factors M~2 in the unstable direction and the stable direction was 1.32 and 1.25, respectively.     

高功率二极管列阵泵浦固体激光泵浦耦合优化设计

高功率二极管阵列泵浦固体激光系统的核心在于泵浦耦合技术,泵浦耦合直接决定了系统的成本、增益能力、增益均匀性、泵浦引发动态波前畸变和泵浦引发动态光束漂移等关键问题。通过对用于高功率二极管列阵泵浦固体激光系统泵浦耦合优化设计的3维光线追迹方法的研究,从二极管发光远场属性出发,建立其理论计算模型,对高功率激光二极管阵列端面泵浦大口径放大器的一种新型耦合方式——二极管列阵拟球面排列、空心镀银导管耦合进行了优化设计,并开展了泵浦耦合效率、泵浦场均匀性、泵浦场传输性等实验研究,实现了72%耦合效率、5 mm内80%传输效率的均匀平顶泵浦耦合场输出,理论计算与实验结果符合较好。     

高功率二极管列阵泵浦固体激光泵浦耦合优化设计

 高功率二极管阵列泵浦固体激光系统的核心在于泵浦耦合技术,泵浦耦合直接决定了系统的成本、增益能力、增益均匀性、泵浦引发动态波前畸变和泵浦引发动态光束漂移等关键问题。通过对用于高功率二极管列阵泵浦固体激光系统泵浦耦合优化设计的3维光线追迹方法的研究,从二极管发光远场属性出发,建立其理论计算模型,对高功率激光二极管阵列端面泵浦大口径放大器的一种新型耦合方式——二极管列阵拟球面排列、空心镀银导管耦合进行了优化设计,并开展了泵浦耦合效率、泵浦场均匀性、泵浦场传输性等实验研究,实现了72%耦合效率、5 mm内80%传输效率的均匀平顶泵浦耦合场输出,理论计算与实验结果符合较好。     

Laser diode pumped bismuth-doped optical fiber amplifier for 1430 nm band

A 24 dB gain bismuth-doped fiber amplifier at 1430 nm pumped by a 65 mW commercial laser diode at 1310 nm is reported for the first time (to our knowledge). A 3 dB bandwidth of about 40 nm, a noise figure of 6 dB, and a power conversion efficiency of about 60% are demonstrated. The temperature behavior of the gain spectrum is examined.     

Laser diode pumped high-energy single-frequency Er:YAG laser with hundreds of nanoseconds pulse duration

We demonstrated a high-energy single-frequency erbium-doped yttrium aluminum garnet(Er:YAG)laser.With1470 nm laser diodes(LDs)as pumping sources,single-frequency laser pulses with energy of 28.6 m J,21.6 m J,and 15.0 m J are obtained at pulse repetition frequency of 200 Hz,300 Hz,and 500 Hz,respectively.As far as we know,this is the highest single-frequency pulse energy with the Er:YAG gain medium.With the ring cavity design,pulse duration is maintained at hundreds of nanoseconds.This high-energy single-frequency laser with hundreds of nanoseconds pulse duration is a prospective laser source for light detection and ranging applications.