Single-frequency laser at 473 nm by twisted-mode technique

We experimentally demonstrate an all solid-state laser producing single-frequency output at 473 nm. Spatial gain hole-burning in the gain material has been eliminated by use of twisted-mode cavity approach. By carefully designing, a V-cavity with two beam waists is chosen to provide the optimum beam radius in the gain medium Nd:YAG and second harmonic generation crystal LBO. A total output power of 105 mW was achieved when the laser was diode-end-pumped at an incident power of 3.5 W; the light-light conversion efficiency is up to 3%.     

1083nm窄线宽单频掺镱光纤激光器

提出了一种低噪声、线宽小于4 kHz、波长为1 083 nm的线形腔单频光纤激光器.该激光器引入了偏振控制器来消除线形腔内的空间烧孔效应,从而抑制了多纵模振荡.实验结果表明:泵浦功率在40～200 mW范围内时,可获得稳定的单纵模振荡,且最大输出功率可达46 mW,光学信噪比大于60 dB,其光光转换效率和斜率效率分别为23％和33.3％％;经过1h的观察,测得的激光输出功率以及光谱不稳定性分别小于3％和0.9％;在整个观察期内,没有出现模式跳跃和模式竞争现象.     

219.3 W CW diode-side-pumped 1123 nm Nd:YAG laser

We demonstrate a high power continuous wave (CW) diode-side-pumped Nd:YAG laser operating at 1123 nm with a plano-plano configuration. By means of precise coating, a single 1123 nm wavelength is achieved. Under the pump power of 1080 W, an output power of 219.3 W is obtained, which corresponds to an optical-optical conversion efficiency of 20.3%. To the best of our knowledge, this is the highest output power for CW 1123 nm laser based on Nd:YAG crystal.     

Nd:LuYAG混晶1123 nm被动调Q激光器

文章报道了一个二极管激光抽运的1123 nm被动调Q激光器. 激光晶体为混晶Nd:LuYAG, 饱和吸收体选为Cr⁴⁺:YAG晶体. 在连续运转情况下, 最高输出功率为2.77 W, 对应的光-光转换效率为29.53%. 调Q运转时, 在9.38 W吸收抽运功率下, 最高输出功率为0.94 W. 脉冲宽度整体在105 ns左右. 在最高吸收抽运功率下, 1123 nm激光的输出重复频率为9.40 kHz, 对应的单脉冲能量可达100 μJ, 高于目前报道的单晶Nd:YAG 1123 nm单脉冲能量, 证明其在能量存储方面较单晶Nd:YAG更具优势. 另外, 据我们所知, 这是关于混晶Nd:LuYAG 1123 nm输出的首次报道.     

Single-frequency laser at 473 nm by use of twisted-mode technique

We experimentally demonstrate an all solid-state laser producing single-frequency output at 473 nm. Spatial gain hole-burning in the gain material has been eliminated by use of twisted-mode cavity approach. By carefully designing, a Z-cavity with two beam waists is chosen to provide the optimum beam radius in the gain medium Nd:YAG and second harmonic generation crystal LBO. A total output power of 85 mW was achieved, when the laser was diode-end-pumped at an incident power of 3.5 W, the light–light conversion efficiency is up to 2.4%.     

High power and highly efficient Nd:YAG laser emitting at 1123 nm

A diode-end-pumped continuous-wave (CW) Nd:YAG laser emitting at 1123 nm is realized efficiently in a 25-mm-long cavity. A composite Nd:YAG (cNd:YAG) crystal is selected as the gain medium. With an incident diode power of 26.1 W, an output power of up to 9.3 W is obtained, corresponding to an optical-to-optical conversion efficiency of 35.6%. The laser performances at 1123 nm are compared between composite Nd:YAG and common Nd:YAG crystals. The results show that composite Nd:YAG is a better choice for 1123-nm laser generations.     

307 W high-power 1018 nm monolithic tandem pump fiber source with effective thermal management

We report a 307 W 1018 nm Yb-doped fiber laser pumped by a single 976 nm laser diode. The cavity slope efficiency is up to 75.9% and the amplified spontaneous emission is suppressed by 54 dB. The beam quality of the output laser has an M2 factor of 1.17. Effective thermal management is considered to ensure the stable operation of our system. The power stability at the maximum output power level is measured during a period of0.5 h and the power fluctuation is less than 0.8%. This architecture can be an effective high brightness pump source of core-pumping high-power fiber amplifiers.     

Single-frequency operation of diode-pumped Yb:KYW at 1003.4 nm and 501.7 nm by intracavity second harmonic generation

Thanks to its high emission cross section around 1000 nm, Yb:KYW is a good candidate for laser operation near 1000 nm as shown in our figure of merit. We demonstrated, for the first time to our knowledge, laser operation of Yb:KYW at 1003.4 nm. The single-frequency operation was achieved in a ring oscillator whereas the second harmonic generation in the blue was carried out with a KNbO₃ crystal put inside the cavity. More than 500 mW at 1003.4 nm and 35 mW at 501.7 nm were produced simultaneously. This visible wavelength corresponds to an iodine transition previously studied with argon ionized lasers for metrological applications. PACS 42.55.Xi; 42.72.Hj; 42.72.Bj     

Simultaneous dual-wavelength oscillation at 1116 and 1123 nm of Nd:YAG laser

We report on to our knowledge the first time a diode-side-pumped simultaneous dual-wavelength Nd:YAG laser at 1116 and 1123 nm. By inserting an etalon to balance the gain and loss, a stable dual-wavelength oscillation is acquired. The numerical simulations for wavelength tuning are discussed by principles of laser threshold and Fabry-Perot etalon. Under the pump power of 250 W, a total output power of 23 W is obtained. Meanwhile, the two components have approximately equal intensities. The beam quality of M² factor was measured to be 7.52.     

Modulation-free acetylene-stabilized lasers at 1542 nm using modulation transfer spectroscopy

We report frequency stabilization of diode lasers using modulation transfer spectroscopy of an acetylene transition (¹³C₂H₂, ₁+₃, P(16)) at 1542 nm. We realize modulation-free acetylene-stabilized lasers with a frequency stability of about 10^–11 and an absolute frequency accuracy of about 20 kHz.This revised version was published online in March 2005. In the previous version, the published online date was missing     

Microchip Nd:vanadate lasers at 1342 and 671nm

As much as 105 mW of single-frequency output at 1342 nm was obtained from a diode-laser-pumped Nd:YVO(4) microchip laser. An intracavity frequency-doubled device generated 10 mW of single-frequency red radiation.     

光子晶体垂直腔面发射850nm波长激光器研究

文章报道了国内首次研制成功的光子晶体垂直腔面发射850nm波长激光器，实现了连续电注入激射．发现器件能否激射直接依赖于光子晶体结构参数，而激光器的阈值、输出功率、输出模式等与光子晶体的晶格常数、占空比、腔的大小等因素有关．     

High-efficiency diode-pumped acousto-optically Q-switched 1123 nm ceramic Nd:YAG laser

A high-efficiency diode-pumped acousto-optically (AO) Q-switched ceramic Nd:YAG (cNd:YAG) laser operating at 1123 nm is demonstrated for the first time. With an incident pump power of 17.11 W and a pulse repetition rate of 30 kHz, an average output power of 5.86 W is obtained. The optical-to-optical conversion efficiency is 34.2% and the slope efficiency is 39.1%.     

Single-frequency cw vertical external cavity surface emitting semiconductor laser at 1003 nm and 501 nm by intracavity frequency doubling

This work reports single-frequency laser oscillation at λ=1003.4 nm of a diode-pumped vertical external cavity surface-emitting semiconductor laser for metrological applications. A low thermal resistance of the semiconductor active component is achieved by solid-liquid interdiffusion bonding onto a SiC substrate. The spectro-temporal dynamics of the laser is theoretically studied. Experimentally, an output power of 1.7 W is demonstrated in free running operation, and up to 500 mW in a true single longitudinal mode. Furthermore, single-frequency laser emission at λ=501.7 nm is obtained by intracavity frequency doubling, resulting in a total output power as high as 62 mW. PACS 42.55.Px; 42.55.Xi; 42.62.Eh; 42.65.Ky     

Single-frequency Yb:YAG non-planar ring oscillator fiber amplifier source at 1030 nm

We report on amplification of a single-frequency Yb:YAG non-planar ring oscillator using Yb-doped fibers. The amplifier system operated at 1030 nm with up to 18.7 W output power, 75% slope efficiency and an M²-value better than 1.1.     

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.     

Properties of continuous-wave 1123 nm laser with diode-side-pumped Nd:YAG

Laser properties of diode-side-pumped Nd:YAG laser operating at 1123 nm are demonstrated. A 1.0 at % Nd-doped Nd:YAG rod with a size of Ø3 × 63 mm² is used as the active medium. Both radial and tangential thermal focal lengths of this side-pumped Nd:YAG rod are determined under lasing condition. The results show that the bifocusing strength of 1123 nm laser is larger than that of 1164 nm laser, and 1123-nm thermal focal lengths are shorter than those of 1064-nm laser due to higher quantum defect. Laser output performances of 1123 nm in terms of stability, output power and beam quality influenced by pump power at different cavity lengths are also discussed with a convex-piano cavity.     

利用双折射滤光片技术获得瓦级单频绿光输出

对两种双折射滤光片选频方案进行了理论分析,给出合理的选频结构.实验中采用简单驻波腔,双KTP /单BP的结构,在8 W的泵浦功率下获得了1.12 W的单频绿光连续稳定输出,并对单频激光器稳定运转与外界微扰之间的关系进行了初步的讨论     

Nd:YAG lasers at 1064 nm with 1-Hz linewidth

Two Nd:YAG lasers are tightly frequency-stabilized to separately located, vertically mounted ultrastable cavities, which are connected by single-mode optical fibers employing fiber phase noise cancellation. The optical heterodyne beat between two independent lasers shows that the linewidth of each laser reaches 1 Hz and the frequency drift is less than 0.3 Hz/s.     

12 W高功率高可靠性915 nm半导体激光器设计与制作

本文设计并制作了一种高效率、高可靠性的915 nm半导体激光器。半导体激光器是光纤激光器的关键部件,为了最大限度地提高器件的电光转换效率,在设计上采用双非对称大光腔波导结构,同时对量子阱结构、波导结构、掺杂以及器件结构进行了系统优化。器件模拟表明,在25℃环境温度下,器件的最高电光转换效率达到67%。采用金属有机气相沉积(MOCVD)法进行材料生长,随后制备了发光区域宽度为95μm、腔长为4.8 mm的激光芯片。测试表明,封装后器件的效率以及其它参数指标达到国际先进水平,在室温下阈值电流为1 A,斜率效率为1.18 W/A,最高电光转换效率达66.5%,输出功率12 W时,电光转换效率达到64.3%,测试结果与器件理论模拟高度吻合。经过约6 000 h的寿命加速测试,器件功率没有出现衰减,表明制作的高功率915 nm激光芯片具有很高的可靠性。