Highly-Efficient Ho:S<Subscript>i</Subscript>Sc<Subscript>2</Subscript>O<Subscript>5</Subscript> Laser Pumped by a Narrow Line-Width Tm:YAP Laser at 1.94 <Emphasis Type="Italic">μ</Emphasis>m

We present a highly-efficient continuous-wave Ho:SSO laser pumped by a diode-pumped Tm:YAP laser with a narrow linewidth (NL) of 0.3 nm. With the free-running (FR) Tm:YAP laser, we obtain a maximum output power of 2.23 W at an absorption pump power of 7.2 W, corresponding to an optical conversion efficiency of 31% and a slope efficiency of 42.6%. With the NL Tm:YAP laser, we obtain a maximum output power of 2.88 W at the same absorption pump power. The optical conversion efficiency increases to 40% when the slope efficiency increases to 55.5%. The output linewidth of the Ho:SSO laser is 0.8 nm when we use the Tm:YAP laser with a narrow linewidth of 1.8 nm pumped by a FR Tm:YAP laser. The beam quality also changes from 1.31 to 1.22.     

Continuous wave operation of singly-doped Ho:LSO laser at room temperature

We present the room-temperature continuous-wave Ho:LSO laser single-pass-end-pumped by a diode-pumped Tm:YLF laser at 1.91 μm in this paper. Under different output couplers of 2.4, 5.0, and 14.0%, the laser output power and output spectrum of Ho:LSO laser operating at room temperature are investigated. The output wavelength of Ho:LSO laser was centered at 2106.5 nm with linewidth (FWHM) of about 3.2 nm. With T = 5.0%, the maximum output power of 2.4 W was achieved under the absorbed pump power of 11.1 W, corresponding to a slope efficiency of 38.0%.     

Diode-pumped high-efficiency Tm:YLF laser at room temperature

High-efficiency continuous-wave (CW) Tm:YLF laser by the dual-end-pumping configuration is presented. Under the total input pump power of 24.0 W, the highest output power reaches 9.8 W in the wavelength range of 1910 - 1926 nm by use of 10% output coupling, corresponding to optical conversion efficiency of 40.9% and slope efficiency of 51.4%. The free-running laser spectrum of Tm:YLF is measured.     

Narrow Linewidth Tm:YLF Laser with Volume Bragg Grating Dual-End-Pumped by Equidirectional-Polarization Fiber-Coupled Laser Diode

We demonstrate a narrow linewidth Tm:YLF laser with a volume Bragg grating (VBG) that was pumped by an equidirectional-polarization fiber-coupled laser diode using a dual-end-pumping configuration. For an optimized output coupler with a radius of curvature of 150 mm and transmission of 15% at a wavelength of 1.91 μm, the maximum output power was 15.6 W for an absorbed pump power of 51.7 W at 1,907.93 nm, and the output had a narrow linewidth of 0.22 nm. This corresponds to an optical-to-optical conversion efficiency of 30.2% and the slope efficiency was 36.7%.     

Stable output, high power diode-pumped Tm:YLF laser with a volume Bragg grating

A stable output, high power diode-pumped Tm: YLF laser operating at 1908 nm with FWHM line width less than 0.1 nm is reported. Using a volume Bragg grating, 41.1 W of output with M ²∼2 under an incident pump power of 111.7 W was achieved, corresponding to an optical-to-optical conversion efficiency of 36.8% and a slope efficiency of 43.2%. A laser wavelength shift of only 0.3 nm with the incident pump power varying from 13.1 W to 111.7 W was observed.     

Efficient high-power Ho:YAG laser directly in-band pumped by a GaSb-based laser diode stack at 1.9 μm

An efficient high-power Ho:YAG laser directly in-band pumped by a recently developed GaSb-based laser diode stack at 1.9 μm is demonstrated. At room temperature a maximum continuous wave output power of 55 W at 2.122 μm and a slope efficiency of 62% with respect to the incident pump power were achieved. For narrow linewidth laser operation a volume Bragg grating was used as output coupler. In wavelength stabilized operation a maximum output power of 18 W at 2.096 μm and a slope efficiency of 30% were obtained. In this case the linewidth is reduced from 1.2 nm to below 0.1 nm. Also spectroscopic properties of Ho:YAG crystals at room temperature are presented.     

Investigation of a High-Beam-Quality Dual-End-Pumped Stable Tm:YLF Laser in Single Rod Geometry

We report a high-beam-quality stable Tm:YLF laser with a single rod crystal. By optimizing the output coupler parameters and regulating an F–P etalon combined with the VBG, we obtain a maximum continuous-wave output power exceeding 15Wwith a wavelength of 1,908.2 nm and a narrow linewidth of 0.18 nm, corresponding to a slope efficiency of 39.4% and an optical-to-optical conversion efficiency of 34.6%; the beam quality factor M² is less than 1.4 at the maximum output power.     

窄线宽1064 nm光纤激光泵浦高效率中红外3.8μm MgO:PPLN光参量振荡器

采用放大1064?nm掺镱光纤激光器作为泵浦源,实现了中红外3.8?μm?MgO:PPLN光参量振荡(OPO)激光输出.在泵浦源中,采用分布式反馈激光器(DFB)作为种子源来实现光纤激光窄线宽的调制,实现线宽2.5?nm到0.1?nm的压缩,最大平均输出功率可达40?W.进一步对不同泵浦线宽条件下中红外3.8?μm?M...     

LD-end-pumped 60 pm linewidth Tm:YLF laser

Narrow linewidth continuous-wave Tm:YLF laser at room temperature with a Volume Bragg grating and double Fabry-Perot etalons by using the end-pumping configuration was presented. The Tm:YLF laser operates at 1907.3 nm with FWHM of approximately 60 pm. We achieved the maximum output power of 1.92 W when the incident pump power of 13.9 W, corresponding to the optical-to-optical conversion efficiency of 13.8% and slope efficiency of 16.4%.     

The output characteristics of double-end-pumped Ho:LuAG laser at room temperature

Continuous-wave (CW) and Q-switched operation of a room-temperature Ho:LuAG laser was resonantly double-end-pumped by a diode-pumped Tm:YLF laser at 1.91 μm. The CW Ho: LuAG laser generated 24.5 W of linearly output at 2094.4 nm with beam quality factor of M ² = 1.11 ± 0.02 for an absorbed pump power of 44.0 W, corresponding to optical-to-optical conversion efficiency of 55.7% and slope efficiency of 60.5%. Under Q-switched operation, a maximum output power of 24.1 W with a slope efficiency of 58.1% at 12 kHz was obtained. Also, the minimum pulse width of 32 ns was achieved, corresponding to the peak power was 37.7 kW.     

Efficient Cr:ZnSe laser with a volume Bragg grating

An efficient and narrow linewidth Cr:ZnSe laser pumped by Tm,Ho:GdVO₄ laser with a volume Bragg grating (VBG) is reported. The Cr:ZnSe laser operated at 2580 nm with emitting linewidth (FWHM) about 0.8 nm. Using the volume Bragg grating, 3.57 W of output was achieved under total incident pump power of 13.1 W, corresponding to optical-to-optical conversion efficiency of 27.3%. By use of conventional mirror, 4.11 W of output was achieved the same incident pump power and the optical-to-optical conversion efficiency is 31.4%.     

Efficient dual-wavelength operation of Nd:LYSO laser by diode pumping aimed toward the absorption peak

By aiming the pump wavelength of the laser diode to the absorption peak at 811 nm of the (Nd 0.005 Lu 0.4975 Y 0.4975 ) 2 SiO 5 (Nd:LYSO) crystal, an efficient dual-wavelength operation at 1 075 and 1 079 nm is obtained. The maximum output power is 702 mW when the incident pump power is 2.53 W, corresponding to an optical conversion efficiency of 27.7% and a slope efficiency of 37.0%     

An Actively Mode-Locked Ho:YAG Solid-Laser Pumped by a Tm-Doped Fiber Laser

An actively mode-locked Ho:YAG laser pumped by a diode-pumped Tm-doped fiber laser is reported.For the cw operation,we obtain the maximum output power of 3.43 W with a central wavelength 2022.2 nm at the maximum incident pump power of 11.4 W,corresponding to a slope efficiency of 34.5%.The beam quality factor M2 is 1.16,and the output beam is close to fundamental TEM_(00) In the case of the CWML operation,a stable pulse train is generated with an average output power up to 3.41 W with a slope efficiency of 34.3%at the incident pump power of 11.4 W and a pulse duration of 294 ps at a repetition rate of 81.92 MHz.In addition,the maximum single pulse energy is 41.6 n J.     

6.17-W continuous wave operation of a 2132-nm c-cut Tm,Ho:YAP pumped by a laser diode of 794.3 nm

Continuous wave (CW) operation of a c-cut Tm (5 at %), Ho (0.3 at %):YAP laser at 2132 nm wavelength were reported in this paper. In the temperature of 77 K, the Tm,Ho:YAP crystal was double end-pumped by a 21.4 W fiber-coupled laser diode (LD) at the center wavelength of 794.3 nm. Different resonator lengths and output couplers for the total pump power were tried. The resonator length was 205 mm, and the maximum CW output power of 6.17 W was acquired, corresponding to an optical-optical conversion efficiency of 28.8% and a slope efficiency of 35.6%.     

Tm:fiber laser in-band pumped Ho:LuAG laser with over 18 W output at 2124.5 nm

We describe efficient operation of a Ho:LuAG laser in-band pumped by a cladding-pumped narrow linewidth Tm fiber laser at ∼1907 nm. With 1.0 at % Ho³⁺-doped LuAG and an output coupler of 6% transmission, the laser had a threshold pump power of ∼0.85 W and generated 18.04 W of continuous-wave output power at 2124.5 nm for 35 W of incident pump power, corresponding to an average slope efficiency with respect to incident pump power of 53.4%.     

紧凑的新型Yb:GdYAB自倍频激光器

报道了一种新型自倍频晶体Yb∶Gd0.2Y0.75(BO3)4(Yb∶GdYAB)在二极管激光器端面抽运条件下的连续光激光运转。为了实现紧凑的新型全固态激光器的激光运转,设计了一个平平谐振腔,两个镜子的分开距离仅为1 cm,在这种腔结构下,得到了中心波长为1044 nm的基频激光输出,当吸收抽运功率为4.22 W时,基频激光的最大输出功率为1.38 W,相应功率曲线最大斜效率为54%。为获得有效的自倍频激光输出,换用了平凹腔进行了自倍频实验。自倍频光运转阈值仅为900 mW,在吸收抽运功率为3.9 W的条件下,得到144 mW的自倍频绿色激光输出,获得从二极管激光器到绿光的直接光-光转换效率为3.7%。实验结果表明Yb∶GdYAB作为一种新型的自倍频晶体,对于紧凑的1μm波段的基频光和自倍频可见光激光器都有着很大的应用潜力。     

激光线宽对单次通过PPMgO:LN晶体倍频效率的影响

通过单次穿过PPMgO:LN晶体产生了2.06 W的780 nm可调谐的连续倍频光. 采用1560 nm的分布反馈式(DFB)半导体激光器、光栅外腔半导体激光器(ECDL)和分布反馈式掺铒光纤激光器(DFB-EDFL)分别作为掺铒光纤放大器(EDFA)的注入光源, 所用的EDFA具有保持窄线宽的功能, 因此可以忽略它对基波线宽的展宽. 研究了激光线宽对单次通过PPMgO:LN 晶体的倍频效率的影响. 控制三台激光器各自注入EDFA的功率一致, 同时也保持EDFA 的输出功率. 在基波功率为12.42 W 时, 使用DFB半导体激光器注入EDFA时得到了1.36 W的780 nm倍频光输出, 转换效率为11.0%; 使用ECDL作为种子源时得到了1.78 W 的780 nm倍频光输出, 转换效率为14.3%; 使用DFB-EDFL作为种子源时得到了2.06 W的780 nm倍频光输出, 转换效率为16.6%. 测得三台种子激光器的线宽分别为1.2 MHz (DFB), 200 kHz (ECDL)和600 Hz (DFB-EDFL). 线宽越窄, 倍频效率越高, 实验结果与理论分析一致.     

A compact efficient continuous-wave self-frequency Raman laser with a composite YVO4/Nd:YVO4/YVO4 crystal

We report a low-threshold continuous-wave self-Raman laser with a composite YVO₄/Nd:YVO₄/YVO₄ crystal. The use of the composite crystal can reduce the thermal effects and achieve the low-threshold and high Raman output operation. The Raman threshold is as low as 2.2 W for the 808-nm diode pump. Under the pump of a diode power of 25.5 W, the highest Raman output of 2.8 W is obtained at 1175 nm, corresponding to a slope efficiency of 12% and a diode-to-Stokes optical conversion efficiency of 11%. The power fluctuation is less than 1.1% under the highest Raman output.     

103 W in-band dual-end-pumped Ho:YAG laser

An efficient 2?μm in-band pumped Ho:YAG laser was demonstrated. The resonator involves two Ho:YAG crystals, each of which was dual-end-pumped by two orthogonally polarized diode-pumped Tm:YLF lasers. The maximum continuous wave output power of 103?W was achieved, corresponding to a slope efficiency of 67.8% with respect to the incident pump power and an optical-to-optical conversion efficiency of 63.5%. Under Q-switched mode, we obtained 101?W laser output at 30?kHz, corresponding to a slope efficiency of 66.2%. The beam quality or M² factor was found to be less than 2.     

Efficient Tm：YAG Ceramic Laser at 2 μm

We demonstrate a high-efficiency continuous-wave Tm： YAG ceramic laser pumped with a Ti：sapphire laser. An output power up to 860mW is obtained under an absorbed pump power of 2.21 W at 785nm, corresponding to a slope efficiency of 42.1% and optical to optical efficiency of 22%. The measured central wavelength is 2012nm.