Double-clad Tm3+-doped silica fiber laser with Bragg grating inscribed directly into active core by femtosecond laser

We report for the first time to inscribe the Fiber Bragg Grating (FBG) in Tm³⁺-doped multimode double-clad silica fiber by 800 nm femtosecond laser with a phase mask. The 1.35 μm period Bragg grating is written into the fiber core, which is responded to the laser center wavelength located at nearly 1960 nm. Continuous wave total output power of 11.5 W is obtained under the launched pump power of 29.8 W, corresponding to a slope efficiency of 45.0% and a conversion efficiency of 38.6%.     

Stable high-power continuous-wave Yb(3+)-doped silica fiber laser utilizing a point-by-point inscribed fiber Bragg grating

We report on a narrowband 5 W cw fiber laser incorporating a point-by-point fiber Bragg grating inscribed into the core of a Yb(3+)-doped double-clad fiber. The laser featured excellent long-term wavelength and power stability (0.3%), as well as a very narrow (15 pm) linewidth, when passive temperature stabilization of the grating was implemented.     

基于飞秒激光直写光纤光栅的掺镱光纤激光器

 利用飞秒激光微加工技术,可以在光纤纤芯内直写出布拉格光栅,它与传统的光纤光栅制作方法相比,具有耗时短、无需光敏光纤、周期可任意设定、光栅稳定性高等优点。采用800 nm钛宝石飞秒激光器,在Hi1060光纤内写入一支8 mm长的布拉格光栅,光纤光栅的周期为2.9 μm,这是中心波长为1 042 nm的八阶光纤布拉格光栅。将所得光栅与一段有源的双包层光纤熔接,作为激光输出镜,利用975 nm的LD光纤模块作为泵浦源,采用端泵浦技术构成双包层光纤激光器。双包层光纤采用Nufern公司镱(Yb³⁺)离子掺杂双包层光纤,光纤长度3 m。所得激光器的输出功率为71.1 W,中心波长1 042 nm,带宽约为0.8 nm。     

基于飞秒激光直写光纤光栅的掺镱光纤激光器

利用飞秒激光微加工技术,可以在光纤纤芯内直写出布拉格光栅,它与传统的光纤光栅制作方法相比,具有耗时短、无需光敏光纤、周期可任意设定、光栅稳定性高等优点。采用800 nm钛宝石飞秒激光器,在Hi1060光纤内写入一支8 mm长的布拉格光栅,光纤光栅的周期为2.9 μm,这是中心波长为1 042 nm的八阶光纤布拉格光栅。将所得光栅与一段有源的双包层光纤熔接,作为激光输出镜,利用975 nm的LD光纤模块作为泵浦源,采用端泵浦技术构成双包层光纤激光器。双包层光纤采用Nufern公司镱(Yb3+)离子掺杂双包层光纤,光纤长度3 m。所得激光器的输出功率为71.1 W,中心波长1 042 nm,带宽约为0.8 nm。     

光纤光栅选频掺Yb3+双包层光纤激光器

利用相位掩模法 ,在D形内包层掺Yb3 双包层光纤一端直接写制出Bragg光栅 ,用作双包层光纤激光器的输出腔镜 .试验得到了线宽为 0 196nm ,波长为 10 5 8 2nm ,最高输出功率为 5 70mW的稳定激光输出 ,解决了激光器中模式竞争造成的输出不稳定现象 .从速率方程出发 ,对激光器的输出功率与抽运功率、光栅反射率的关系以及最佳光纤长度进行了理论分析 ,结果与实验符合很好     

光纤光栅选频掺Yb3+双包层光纤激光器

利用相位掩模法，在D形内包层掺Yb3+双包层光纤一端直接写制出Bragg光栅，用作双包层光纤激光器的输出腔镜.试验得到了线宽为0.196nm，波长为1058.2nm，最高输出功率为570mW的稳定激光输出，解决了激光器中模式竞争造成的输出不稳定现象.从速率方程出发，对激光器的输出功率与抽运功率、光栅反射率的关系以及最佳光纤长度进行了理论分析，结果与实验符合很好. 关键词： 双包层光纤光栅 掺Yb3＋双包层光纤激光器 相位掩模 速率方程     

20 W single-mode Yb3+ -doped phosphate fiber laser

We report the demonstration of the first, to our knowledge, cladding-pumped continuous-wave Yb(3+)-doped phosphate-glass fiber laser. Phosphate hosts are of interest because they can be much more heavily doped than silica, and because of the possibility that they may have a higher photodarkening threshold. In an 84.6 cm double-clad fiber doped with 12 wt. % of Yb(2)O(3) and laser-diode pumped at 940 nm, nearly 20 W of single-mode 1.07 microm output power was generated with 60.2 W of absorbed pump power. The measured dependence of the output power on pump power is in excellent agreement with simulations.     

Yb3+-doped double-clad fiber laser with all fiber cavity

A novel all fiber cavity Yb3+-doped double-clad fiber laser (DCFL) based on two double-clad fiber (DCF)Bragg grating is presented. The fiber Bragg gratings (FBGs) as the input and output mirrors have been formed in Yb3+-doped DCF with the phase-mask method, and their reflectivities are 99% and 22%,respectively. When the input pump power is 417 mW, the maximum output power is 144 mW with linewidth ＜0.1 nm at the wavelength of 1.057μm, over 40-dB signal-to-noise ratio (SNR), and 50.8% slope efficiency.     

全光纤超短脉冲掺Yb3+光纤环形激光器

讨论了自启动被动锁模掺Yb3+光纤环形激光器产生短脉冲的机理,并研制出全光纤结构超短脉冲掺Yb3+光纤环形激光器.采用两个976nm半导体激光器级联抽运作为抽运源,高掺杂浓度掺Yb3+光纤作为增益介质,利用光纤的非线性偏振旋转效应,得到自启动、十分稳定的ps量级锁模光脉冲.激光器锁模阈值功率260mW,输出功率25mW,锁模光脉冲中心波长1056nm,3dB带宽11.7nm,重复频率20MHz.与其他结构光纤激光器相比,这种全光纤结构具有更高的效率和更好的稳定性.     

Self-mixing effect in Yb3+ doped DBR fiber laser with different linewidth enhancement factor

We present a self-mixing interference model approach to stimulate the self-mixing interference in YDBR fiber laser with optical self-mixing interference operating in the weak feedback regime. The self-mixing interference model includes Yb³⁺ doped fibers pumped at 920 nm, with distributed Bragg reflector mirrors at both fiber ends and external reflector. Using the quasi-analytical YDBR fiber laser model and self-mixing three-mirror cavity model, the output power expression is deduced and the Peak-to-Peak values and asymmetry values of self-mixing waveform at different linewidth enhancement factor have been studied in detail.     

High-power and wavelength-tunable operation of an Er,Yb fiber laser using a volume Bragg grating

Efficient high-power operation of double-clad Er,Yb-doped fiber lasers with fixed-wavelength and wavelength-tunable resonator configurations using volume Bragg gratings for wavelength selection are reported. The fixed-wavelength laser yielded a maximum output power of 103 W at 1552.6 nm with a linewidth of ~0.4 nm (FWHM) for a launched pump power of 290 W at 976 nm. The wavelength-tunable laser could be tuned from 1528 to 1550 nm with a linewidth of 0.2 nm (FWHM) and with output power in the range 30-38 W for a launched pump power of 120 W. The prospects for further improvement in performance are considered.     

Widely tunable,narrow linewidth Tm: YAG ceramic laser with a volume Bragg grating

We report on a widely tunable, narrow linewidth operation of a Tm:YAG ceramic laser. A volume Bragg grating is used in the cavity as a folding mirror for wavelength selection. The wavelength is tuned from 1956.2 to1995 nm, leading to a total tuning range of 38.7 nm. The linewidth is around 0.1 nm over the whole tuning range. A maximum output power of 1.51 W at 1990.5 nm is achieved at 37.8 W absorbed pump power.Different saturation behaviors are observed in the laser performances at different wavelengths.     

High energy giant chirped passively mode-locked Yb3+-doped fiber laser with nanoseconds to picoseconds pulses

We report an all normal dispersion low repetition rate high energy passive mode-locked ytterbium-doped fiber laser with output pulses duration ranging from nanoseconds to picoseconds. The mode-locking mechanism of the laser is based on nonlinear polarization evolution and strong pulses shaping with a cascade long-period fiber grating bandpass filtering in highly chirped pulses. The laser generates highly stable pulses duration from 2.62 ns to 315 ps with a maximum pulse energy of 49.5 nJ and 2.5435 MHz repetition rate.     

High-peak-power operation of a Q-switched Tm3+-doped silica fiber laser operating near 2 microm

A peak output power of greater than 4.1 kW and a pulse duration at FWHM of 150 ns have been obtained in a Q-switched Tm3+-doped silica fiber laser in the wavelength region near 2 microm when the laser was pumped with a Nd:YAG laser operating at 1.319 microm. An acousto-optic modulator was used as a Q-switching element and operated at repetition rates of as much as 30 kHz. A core diameter of 17 microm was used to increase the laser gain volume, permitting high-pump-power absorption and an output of high pulse energy and peak power. Stimulated Brillouin scattering was directly observed in the output pulse, and as much as 10 orders of stimulated Brillouin scattering was recorded. This is the first report to the authors' knowledge of high-peak-power operation of a Tm3+-fiber laser.     

8.6W掺Yb3+双包层光纤激光器的研究

采用多模大功率半导体激光器泵浦掺Yb双包层D型光纤,详细研究了输出功率与泵浦功率的关系,获得了1.09μm,功率为8.6W的激光输出.     

高效掺Yb3+双包层光纤激光器的研究

采用多模大功率半导体激光器泵浦掺Yb双包层D型光纤,详细研究了输出功率与泵浦的关系,使用5m长多模光纤,获得了1.07μm,功率为7.2W的激光输出。     

Efficient operation of double-clad Yb3+-doped fiber lasers with a novel circular cladding geometry

A highly efficient double-clad Yb3+-doped fiber laser with a novel cladding geometry is described. A round double-clad fiber with a small D-shaped hole for breaking a circular symmetry in a cladding combines the advantages of ease of manufacture and handling round fibers with efficient absorption of pump light. Fiber lasers with a double-D cladding shape and a D-hole cladding are compared. We report what are to our knowledge the highest slope efficiencies of 73% and 69%, respectively, pumping at 915 nm. Output powers in excess of 13 W are demonstrated.     

Optical bifurcated fiber diode-pumping for two-wavelength laser operation with the Yb3+-doped GdAl3(BO3)4 birefringent crystal

Thanks to diode pumping through an optical bifurcated fiber, we take benefit of the birefringence of the Yb³⁺-doped GdAl₃(BO₃)₄ crystal to get two-polarization and two-wavelength laser operation both in CW and in passive Q-switch regimes. Typical differential slopes are 54% and 30% respectively for the o- and e-waves. In the pulse regime the two o- and e-pulses are synchronous but not simultaneous. Free running laser emissions near 1040 and 1046 nm for the e- and o-waves respectively were obtained with 2.5 nm FWHM.     

高能、超短脉冲、可调谐激光器用掺镱氟磷酸盐玻璃研究进展

Yb^3 与其它稀土离子相比有最简单的能级结构，这使它具有一些独特的性质，如避免激发态吸收，消除上转换和浓度猝灭等，因此它是高能输出激光器介质的理想掺杂离子。氟磷玻璃综合了氟化物玻璃和磷酸盐玻璃的优点，可降低磷酸盐的声子能量，改善其易吸湿性；提高氟化物玻璃的物理化学性能等，这使它成为稀土掺杂可调谐光纤激光器的很好的掺杂介质。众多研究表明，Yb^3 掺杂氟磷玻璃是一种很有前途的激光工作物质。本文总结了Yb^3 掺杂氟磷玻璃的特点，性质，结构及存在的问题。     

Radio-frequency interrogation of a fiber Bragg grating sensor in the configuration of a fiber laser with external cavities

A fiber laser sensor, which consists of two coupled cavities based on three fiber Bragg gratings (two of them acting as sensing elements) and is interrogated via the longitudinal mode beating frequency, is presented. The two resonant cavities have lengths of 4250 m and 4297 m, respectively. Their beating frequency is of the order of 24 kHz, and its shift as a function of the variation of the period of one (or both) of the sensing gratings, induced by strain or temperature changes, can be measured by a radio-frequency analyzer. The system is suitable for long-distance sensing with high spatial resolution and high sensitivity.