1319-nm single-frequency output from dif fusion-bonded monolithic nonplanar Nd:YAG ring resonator with undop0ed end

An efficient 1 319-nm Nd:YAG single-frequency laser is demonstrated in a diffusion-bonded nonplanar ring oscillator (NPRO) with an undoped end. The thermal model of diffusion-bonded NPRO is generated to analyze the temperature field and thermal focal length. A stable single-frequency output power of up to 1.55 W is obtained at 1 319 nm.     

6.1 W single frequency laser output at 1645 nm from a resonantly pumped Er:YAG nonplanar ring oscillator

A monolithic 1645 nm Er:YAG nonplanar ring oscillator (NPRO) resonantly pumped by a 1532 nm fiber laser is demonstrated. For reducing the energy-transfer upconversion effect, a 0.5% doped Er:YAG nonplanar crystal was used. An up to 6.1 W single frequency laser output at 1645 nm was obtained, with a slope efficiency of 55.2% and an optical efficiency of 48.0%. The linewidth of the Er:YAG NPRO was 14.4 kHz.     

Passively Q-switched single-frequency output from a diffusion-bonded monolithic Nd:YAG non-planar ring oscillator

A compact monolithic Nd:YAG non-planar ring laser with diffusion-bonded Cr4+:YAG is demonstrated,and high stable pulsed single-frequency laser at 1.06 μm is realized.Theoretical analysis and simulation results of pulsed laser parameters are illustrated.14.96-kW maximum peak power,pulse-width of 4.8 ns is achieved for single-frequency operation.     

1.6 W of single-mode output power from a novel power-scaling scheme for monolithic nonplanar ring lasers

A novel monolithic ring laser with high potential for power scaling, the disk nonplanar ring oscillator, is presented. We achieved power scaling by reducing the pump-light-induced aberrations. The basic idea of our approach is to attach a thin Nd:YAG disk to an undoped nonplanar YAG ring resonator while the other side of the disk is mounted on a heat sink. First promising experiments have demonstrated a single-frequency cw output power of 1.6 W at 1.06 microm with a slope efficiency of 45%. Power scaling to several watts seems to be possible.     

Laser-diode-pumped phosphosilicate-fiber Raman laser with an output power of 1 W at 1.48 mum

An all-fiber 1.48-mum generator based on a laser-diode-pumped Yb-doped double-clad laser and a cascaded Raman wavelength converter has been developed. Second-order Raman Stokes radiation was generated in a phosphosilicate-fiber resonator formed by two pairs of Bragg gratings. A slope efficiency of the Raman converter of 48% with respect to the power emitted by the double-clad Yb laser has been achieved. We obtained an output power of 1 W at a slope efficiency of 34% with respect to the laser-diode array power, with a total optical-to-optical efficiency of 23%.     

In-band pumped highly efficient Ho:YAG ceramic laser with 21 W output power at 2097 nm

We report on the high-power and high-efficiency operation of a polycrystalline Ho:YAG ceramic laser in-band pumped by a Tm fiber laser at ~1907 nm. Lasing characteristics of a 1.5 at.% and a 2.0 at.% Ho3?-doped YAG ceramic were investigated and compared. Using an output coupler of 6% transmission, over 21.4 W of cw output power at 2097 nm has been generated with the 1.5 at.% doped Ho:YAG ceramic under 35 W of incident pump power, corresponding to an average slope efficiency with respect to the incident pump power of 63.6% and an optical-to-optical conversion efficiency of 61.1%.     

二极管泵浦1064nm单频Nd:YAG激光器输出功率稳定控制系统设计

介绍了激光二极管(LD)端面泵浦1064 nm单频Nd:YAG激光器的工作原理和结构特点,分析了影响这种固体激光器输出功率稳定性的主要因素,设计并实验研究了一种用于稳定该激光器输出功率的控制方案.该方案在严格控制LD和Nd:YAG晶体工作温度的条件下,当单频Nd:YAG激光器的输出功率波动时,根据LD输出功率与其注入电流成正比这一变化规律,利用获得的功率误差信号反馈控制LD的注入电流,即可稳定单频Nd:YAG激光器的输出功率.实验结果表明:当LD泵浦1064 nm单频Nd:YAG激光器的输出功率约为11.5 mW时,采用所设计的控制系统,可使激光输出功率稳定性在130 min内优于1.3%.     

100 W, single-frequency operation of an injection-locked Nd:YAG laser

We have built a single-frequency Nd:YAG laser capable of producing an output power of 101 W by injection locking a slave laser that can emit an output power of 121 W in the free-running state to a 2-W master laser. We confirmed that the output mode was diffraction limited and linearly polarized.     

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.     

Passively Q-switched Nd:YAG ring lasers with high average output power in single-frequency operation

Applying Cr(4+):YAG saturable absorbers, we demonstrate efficient passively Q -switched operation of diode-pumped Nd:YAG lasers with a maximum average output power of more than 800 mW. Pulse durations below 3 ns, energies of 70 muJ, and peak powers of 30 kW are observed with kilohertz repetition rates. Single-frequency operation is accomplished for all output powers by a nonplanar ring geometry.     

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.     

Analysis of optical axis variations in monolithic nonplanar ring laser

A mathematical model of the mirror misalignment of a four-equal-sided nonplanar ring cavity is established in this letter.The variations in the optical axis are discussed through an augmented 6×6 ray matrix formulation.Numerical analysis shows that the self-consistence of the optical axis can always be obtained because of the thermal e?ects in any case of mirror misalignment.For a fabricated design,optical axis variations always appear.The influence of thermal e?ects(i.e.,pump power) on optical axis variations are studied.The tilt of the optical axis remains constant,whereas its decentration varies with pump power.Further analysis shows that the actual closing point of the optical axis moves close to the ideal point as the pump power increases.The theoretical analysis proposed is proven and validated by the experimental results.     

In-band pumped Er:YAG ceramic laser with 11 W of output power at 1645 nm

We report on a high power polycrystalline Er:YAG ceramic laser in-band pumped by a cladding-pumped Er, Yb fiber laser wavelength locked at 1532 nm with a volume Bragg grating. Using 1.0 at % Er³⁺-doped ceramic as the gain medium and an output coupler of 10% transmission, the laser had a threshold pump power of ∼1.5 W and generated 11 W of continuous-wave output at 1645 nm for 23.3 W of incident pump power at 1532 nm, corresponding to a slope efficiency with respect to incident pump power of 51%.     

Narrowband Er:YAG nonplanar ring oscillator at 1645 nm

We report 1645 nm narrowband operation of a monolithic Er:YAG nonplanar ring oscillator resonantly pumped at 1532 nm. Unidirectional cw power up to 0.5 W was obtained with a measured linewidth of 21 kHz.     

885 nm pumped,high efficiency single-frequency Nd:YAG ring laser

We report an efficient single-frequency ring laser pumped directly into emitting level by a fiber-coupled laser diode (FCLD) at 885 nm for the first time. 4.8 W laser at 1064 nm was obtained in a 0.7 at % Nd:YAG with 63% slope efficiency and 51.7% light-light efficiency in absorbed pump power. At the same time, the line width of the longitudinal mode was about 50 MHz, and the beam was nearly diffraction-limited with M2 ≈ 1.07.     

Diode-end-pumped linear-polarized single-frequency Tm:YAG laser at room temperature

By using two solid uncoated etalons, we present a diode-pumped linear-polarized single-frequency Tm:YAG laser operating at 2 μm. Placing one 0.1 mm F-P etalon at nearly Brewster angle in the cavity, the linear-polarization laser is achieved. The other 1 mm F-P etalon was turned in the range of very small angle, single-longitudinal-mode (SLM) could be obtained. The maximum output power of linear-polarized single-frequency laser of 60 mW is achieved at the wavelength of 2013 nm. The degree of the polarization is over 30 dB. Long-term frequency stability was also investigated, with the results of wavelength fluctuation about 2.55 × 10⁻¹³ m within 3 min and frequency change about 18.86 MHz, corresponding to a frequency stability of 1.27 × 10⁻⁷.     

All-solid-state continuous-wave frequency doubling Nd:YAG/LBO laser with 8.2 W output power at 660 nm

An efficient and compact red laser at 660 nm is generated by intracavity frequency doubling of continuous wave (CW) laser operation of a diode pumped Nd:YAG laser at 1319 nm under the condition of suppression the higher gain transition near 1064 and 1319 nm under the condition of suppression the higher gain transition near 1064 and 1338 nm. With 40 W diode pump power and a frequency doubling crystal LBO, as high as 8.6 W of CW output power at 660 nm is achieved, corresponding to an optical-to-optical conversion efficiency of 21.5% and the output power stability in 8 h is better than 2.73%. To the best of our knowledge, this it the highest conversion efficiency of watt-level laser at 660 nm generated by intracavity frequency doubling of a diode end pumped Nd:YAG laser at 1319 nm.     

A 20 W Cr, Tm, Ho: YAG laser

A 2.1 μm Cr³⁺, Tm³⁺, Ho³⁺ : YAG laser is operated with an output power of 20 W at 12 Hz. The laser output is successfully transmitted through a silica fibre. The laser system was designed based on the technology of an alexandrite laser oscillator.     

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%.     

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.