Diode-pumped Tm:LuAG laser at room temperature

The lasing characteristics of Tm：LuAG at room temperature are reported. The maximum output power at 2.023-μm wavelength is 4.91 W and the slope efficiency is 25.39%. The mode matching between pump mode and laser mode is optimized by changing the pump beam waist radius and its location. Different output couplers are used to realize the optimal laser output. The relationship between operation temperature and output power is also discussed.     

Diode-pumped Q-switched Tm:LuAG ring laser operation at room temperature

2-μm lasers with high pulse energy and long pulse width of hundreds of nanoseconds are needed urgently in the accurate wind velocity lidar systems. This paper presented the acoustic-optical Q-switched Tm:LuAG laser performance in a pulsed-laser-diode end-pumping figure-eight ring resonator structure. Pulse energy and pulse width are investigated with the increasing of the incident pump energy at different repetition rate operation. Maximum energy of 3.3 mJ with the pulse width of 199 ns and 1.8 mJ with pulse width of 293 ns are obtained at the repetition rate of 20 and 50 Hz, respectively. Under Q-switched operation, the peak output wavelength is 2.022 μm at all time, and the beam quality factors are lower than 2 times diffraction-limited measured by a knife-edge traveling method.     

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%.     

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%.     

LD-pumped actively Q-switched Tm,Ho:YLF laser at room temperature

We have investigated acoustic-optical Q-switched Tm,Ho:YLF laser end-pumped by a laser-diode. At room temperature, a 2.067 μm wavelength pulsed output is realized. Average output power, single pulse energy and pulse-width are measured at different incident pump powers and pulse repetition frequencies. When the incident pump power is 2.8 W, a maximum average output power of 189 mW is obtained at the repetition frequency of 9 kHz, and this corresponds to an optical conversion efficiency of 6.8%. The maximum single pulse energy of 65μJ, the shortest pulse-width with full-width at half-maximum (FWHM) of 138 ns and the maximum peak power of 470 W are obtained at the pulse repetition frequency of 1 kHz.     

Diode-pumped single frequency Tm,Ho:YLF laser at room temperature

A diode-pumped single frequency Tm,Ho:YLF laser operating at an eye-safe wavelength of 2 μm has been developed. Temperature of the laser crystal was controlled at room temperature with a thermoelectric cooler. The line-width narrowing elements were two solid uncoated fused silica etalons whose thicknesses were 1 and 0.1 mm, respectively. Continuous wave single frequency power of 113 mW was obtained.     

Achieving single-longitudinal-mode output about Tm:YAG laser at room temperature

We report on the single-longitudinal-mode Tm:YAG laser with a volume Bragg grating pumped by laser diode at room temperature. The maximum SLM power of 142 mW was achieved under incident pump power of 3.22 W. The central wavelength was 2012.6 nm accords with the resonant wavelength of the VBG. Three cavity lengths were used to achieve high efficiency and clear spectrum. The maximum output power were measured to be 450.5, 451.4, and 457.3 mW at incident pump power of 3.22 W, corresponding to a slope efficiency of 17.1, 16.9, and 16.7% for the cavity length of 30, 40, and 50 mm, respectively. 40 mm cavity length having the cleanest spectrum among the three was used for SLM laser with one 1 mm F-P etalon inserted into the cavity.     

激光二极管端面抽运室温Tm,Ho:YLF连续固体激光器

报道了激光二极管端面抽运Tm，Ho：YLF固体激光器的输出特性.室温下，选用不同透过率的输出耦合镜进行了实验研究，确定了最佳输出耦合镜透过率为2%. 利用小孔扫描的方法，得到了激光远场的光强分布，证明激光为基横模输出，并且给出了热焦距随抽运功率的变化关系.通过在激光谐振腔内插入两个固体Fabry-Perot标准具的方法，获得了2μm激光的单频输出，阈值功率为250mW，在抽运功率为2.8W时，单频输出功率为118mW.此单频激光器可用作激光振荡器和激光放大器的种子源. 关键词： 激光光学 激光二极管 Tm Ho:YLF固体激光器 单频     

Single-frequency, Q-switched Ho:YAG laser at room temperature injection-seeded by two F-P etalons-restricted Tm, Ho:YAG laser

We demonstrated a 1.91 μm pumped, injection-seeded Q-switched Ho:YAG laser operating at room temperature. By inserting two Fabry-Perot etalons into the laser cavity, single-frequency Tm, Ho:YAG seed lasing was achieved at a wavelength of 2090.9 nm, with a typical output power of 60 mW. Single-frequency, nearly transform-limited Q-switched operation of the Ho:YAG laser was achieved by injection seeding. The output energy of the single-frequency Q-switched pulse is 7.6 mJ, with a pulse width of 132 ns and a repetition rate of 100 Hz. We measured the pulse spectrum, half-width of which was 3.5 MHz, by a heterodyne technique.     

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.     

Optical bistability effects in a Tm,Ho:YLF laser at room temperature

We demonstrate strong optical bistability in a 2 microm continuous-wave Tm,Ho:YLF laser pumped by a 792 nm laser diode near room temperature. The bistable region is as much as 100 mW wide at 283 K and can be controlled by the temperature of the laser crystal. The influence of crystal temperature on the characteristics of optical bistability is obtained. The influence of the pump-to-mode ratio on the bistable characteristics of the laser is also discussed. To our knowledge this is the first report of optical bistability effects in Tm,Ho:YLF lasers.     

Room temperature single-frequency output at 2118 nm from a diode-pumped Tm,Ho:YAP laser

A diode end-pumped single-frequency Tm, Ho:YAP laser at room temperature was reported. We demonstrated a single-frequency Tm, Ho:YAP laser at 2118.09 nm wavelength with output power up to 57 mW using two Fabry-Perot intracavity etalons. The optical conversion efficiency is 2.0% and the slope efficiency is 12.7%. The measured full width at half maximum linewidth was <7.5 pm limited by the resolution of the scanning Fabry-Perot etalon used to make the measurement. The wavelength was demonstrated to be stable to about 2 pm over 40 s time periods limited by the temperature stability of the laser. The single-longitudinal-mode (SLM) laser can be used as a seed laser for coherent wind measurements and differential absorption LIDAR systems.     

Room temperature single-frequency output from a diode-pumped Tm,Ho:YAP laser

Single-frequency operation in the range of 2102.45-2102.54 nm and 2130.72-2130.82 nm is demonstrated from a Tm,Ho:YAP laser at room temperature. To our knowledge, this is the first time a room temperature single-frequency Tm,Ho:YAP laser of up to 72.6 mW at 2102.5 nm with Fabry-Perot etalons has been obtained. Regulating the elevation angle of the two etalons, 42.0 mW at 2130.8 nm was obtained. The single-longitudinal-mode laser can be used as a seed laser for coherent wind measurements and differential absorption lidar systems.     

Injection-seeded Tm:YAG laser at room temperature

The solid-state, tunable, narrowband, high pulse energy and high reliability lasers are attractive source for LIDAR system. In this paper, we demonstrated a diode pumped injection-seeded 2 μm Tm:YAG laser. By inserting two F-P etalons into the laser cavity, linear-polarized single-frequency seed-laser was achieved at a wavelength of 2013 nm, with a maximum output power of 60 mW. Long-term and short-term frequency stability for the seed-laser were 1.27 × 10^− 7 and 97 Hz/μs, respectively. High power Q-switched laser was operated using a bowtie cavity, the bidirectional output of which was favorable for the injection-seeded. After injecting the seed-laser to the power-laser, single-frequency, nearly transform-limited pulsed 2 μm laser was obtained. As much as 2.0 mJ output energy was achieved at an operating repetition rate of 15 Hz, with a pulse width of 356.2 ns.     

Q-switched Ho:YAlO<Subscript>3</Subscript> laser pumped by Tm:YLF laser at room temperature

A Q-switched high efficient Ho:YAlO₃ (Ho:YAP) laser pumped by a diode-pumped Tm:YLF laser at room-temperature is realized. The maximum output energy reaches 1.58 mJ under the repetition frequency of 5 kHz, when the incident pump power is 15.6 W. The pulse width is 22 ns. The wavelength is 2118 nm when the transmission of output coupler is 30%. The beam quality factor is M ² ∼ 1.39 measured by the traveling knife-edge method.     

Diode-pumped room temperature single longitudinal mode lasing of Tm,Ho:YLF microchip laser at 2050.5 μm

Room-temperature operation of a single longitudinal-mode c-cut Tm(6%), Ho(0.4%):YLF microchip laser is reported. An incident pump power of 713 mW is used to generate the maximum single-frequency output power of 17 mW at 2050.5 nm, which corresponds to the slope efficiency of 10%.     

A ring ZnGeP2 optical parametric oscillator pumped by a Ho:LuAG laser

We have demonstrated that we believe to be the first ring ZnGeP₂ (ZGP) optical parametric oscillator (OPO) pumped by a pulsed Ho:LuAG laser. The maximum output power of the ring ZGP OPO laser was 5.51 W at 13.1 W incident Ho pump power, corresponding to a slope efficiency of 59.0 %. The ZGP OPO laser produced 14 ns mid-infrared pulses in the 3.72–4.01 and 4.37–4.75 μm spectral regions simultaneously. In addition, the continuous wave Ho:LuAG laser generated 26.5 W of linearly output at 2,094.4 nm at the absorbed Tm pump power of 49.9 W.     

Continuous-wave Ho:GdVO4 laser pumped by Tm-doped fiber laser with a fiber Bragg grating at room temperature

We reported the Ho:GdVO₄ laser pumped by Tm-doped laser with a fiber Bragg grating. 2.03 W continuous-wave Ho:GdVO₄ laser output power is obtained under 10.5 W incident pump power, with the optical-to-optical conversion efficiency and slope efficiency of 19.3% and 32.3%, respectively, at 7 °C. We can see that, the lower the temperature is, the better the laser output character is. The beam quality factor is M² ∼ 1.29 measured by the traveling knife-edge method.     

Diode-end-pumped Tm,Ho:YVO<Subscript>4</Subscript> microchip laser at room temperature

Room temperature Tm, Ho:YVO₄ microchip laser operated around 2 μm was demonstrated for the first time to our knowledge. At a heat sink temperature of 283 K, a maximum output power of 47 mW was obtained by using a 0.25 mm length crystal at an absorbed pump power of 912 mW, corresponding to a slope efficiency of 9.1%. Increasing the temperature to 288 K, as much as 16.5 mW 2052.3 nm single-longitudinal-mode laser was achieved. The M ² factor was measured to be 1.4.