共查询到20条相似文献,搜索用时 15 毫秒
1.
We report on high-power fiber lasers based on index-guiding, all-solid neodymium-doped (Nd-doped) phosphate photonic crystal fiber (PCF) with a hexagonal-shaped inner cladding. The optimum fiber laser with a 36 cm length active fiber, generated up to 7.92 W output power at 1053 nm, which benefited from a high absorption coefficient for pump power due to its noncircular inner cladding. The guiding properties of the all-solid PCF were also investigated. A stable mode with a donut-shaped profile and a power-dependent laser beam quality have been observed experimentally and analyzed. 相似文献
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In order to improve the performance of the double-clad fiber laser, the optimum laser length needs to be estimated prior to the experiment. Previous expressions for the optimum length of fiber laser have been established under some assumptions, such as the output power without laser scattering loss and the pump power without reflection in the output-end. In this work, the issue of optimum laser length has been analyzed theoretically based on the strongly pumped fiber laser model. An extended expression for the optimum length of the linear cavity Yb3+-doped double-clad fiber laser is obtained. The respective effects of the laser scattering loss, the pump power, the Yb3+ dopant concentration, and the pump reflection on the optimum laser length are identified. 相似文献
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提出了一种基于高掺杂硅酸盐增益光纤、输出波长为1 064nm的超短腔单频光纤激光器.该单频光纤激光器采用分布布拉格反射式腔型结构,有效腔长为2cm,其增益介质为1.1cm长的高浓度掺Yb3+光纤.通过恰当的温度控制,获得了线宽为4.8kHz的稳定单频激光输出.当注入泵浦光为378mW时,输出功率为13mW,斜效率为3.4%.在频率大于1 MHz时,测得该光纤激光器的相对噪声强度值约为-132dB/Hz.采用主振荡功率放大结构,对该单频光纤激光器的输出功率进行放大.当放大增益光纤长度选取为56cm时,得到了325mW的最大输出功率,其斜效率为52.8%. 相似文献
4.
A high efficient LD (laser diode) pumped Tm3+ doped double clad silica fiber laser with an intravacity biconical taper was reported. A biconical taper located ~3 cm from the output end of the fiber laser was fabricated by heating and stretching method with a length 1.5 cm and waist diameter ~20 µm. The slope efficiency was 49.8% with respected to the launched pump power, and the maximum output power was 1.97 W. Pre and post output laser power ratio was ~10. This fiber laser was compared with other three biconical tapered fiber lasers (the same fiber with different tapers) and a uniform geometry fiber laser. With intracavity biconical tapers, fiber lasers’ thresholds were ~1 W higher than the fiber laser without the taper (1.97 W). The pump end’s slope efficiencies of fiber lasers with tapers were 3–5% in contrast with 37.6% of the uniform one. After tapered, the pre and post laser power ratios were much higher than the un-tapered one’s, but not changed much with the launched pump power. 相似文献
5.
Nicholson JW Bise R Alonzo J Stockert T Trevor DJ Dimarcello F Monberg E Fini JM Westbrook PS Feder K Grüner-Nielsen L 《Optics letters》2008,33(1):28-30
Supercontinuum extending to visible wavelengths is generated in a hybrid silica nonlinear fiber pumped at 1560 nm by a femtosecond, erbium-doped fiber laser. The hybrid nonlinear fiber consists of a short length of highly nonlinear, germano-silicate fiber (HNLF) spliced to a length of photonic crystal fiber (PCF). A 2 cm length of HNLF provides an initial stage of continuum generation due to higher-order soliton compression and dispersive wave generation before launching into the PCF. The visible radiation is generated in the fundamental mode of the PCF. 相似文献
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线形腔掺铒光纤激光器输出特性的理论研究 总被引:5,自引:0,他引:5
通过求解速率方程,从理论上详细地分析了形腔掺铒光纤激光器输出特性,得到了稳定条件下激光器阈值泵浦功率,输出功率和斜率效率的解析表达式;给出了构造线形腔掺铒光行激光器所需掺铒光纤最短长度和最佳长度的表达式。 相似文献
9.
数值分析了掺镱单模光纤放大器的最佳增益光纤长度,并在实验上对掺镱单模光纤放大器和光栅对压缩器进行了研究。以最大平均输出功率为7 mW、重复频率为25.4 MHz、脉宽为56 ps的被动锁模环形腔掺镱光纤激光器作为种子脉冲,用250 mW的976 nm单模半导体激光器分别泵浦3种不同长度的掺镱单模光纤,对种子光进行放大,并用光栅对压缩器对放大后的脉冲在不同光栅距离上进行了压缩实验研究。当掺镱单模光纤长度为1.2 m时得到了较好的放大效果,种子脉冲被放大到140 mW,相应的增益为13 dB,放大后的单脉冲能量为5.5 nJ。在光栅距离为14.1 cm时获得了最短440 fs的脉冲,压缩后的功率为43 mW,相应的峰值功率为3.8 kW。 相似文献
10.
Nonlinear-polarization-rotation based multiwavelength erbium-doped fiber lasers with highly nonlinear fiber 总被引:1,自引:0,他引:1
A multiwavelength erbium-doped fiber laser based on nonlinear polarization rotation with incorporation of a highly nonlinear
fiber has been demonstrated. Stable multi-wavelength operation at room temperature is realized owing to the intensity-dependent
transmission in fiber laser with nonlinear-polarization-rotation effect. And benefiting from the four-wave mixing in the highly
nonlinear fiber, the uniformity and stabilization of the output multi-wavelength lasing have been greatly improved, in comparison
with similar laser using single-mode fiber. Moreover, the wavelength spacing can be arbitrarily chosen according to the requirement
through changing the PMF length. 相似文献
11.
A quasi-three-level Yb-doped single-mode fiber laser at 980 nm by adopting two 0° fiber ends as cavity mirrors generated a
total output power of 1.32 W with the slope efficiency of 75.3%. The fiber length was 36.5 cm close to the optimal theoretical
fiber length. The corresponding optical conversion efficiency was 66% from the incident pump power at 946 nm to the laser
power at 980 nm. Through frequency-doubling with BIBO crystal, a total output power of 15 mW at 490.8 nm was obtained. 相似文献
12.
Influences of cavity dispersion distribution on the output pulse properties of an all-normal-dispersion fiber laser 下载免费PDF全文
《中国物理 B》2015,(7)
In this paper, the influences of the dispersion distribution in the cavity on the output pulse properties of the all-normaldispersion(ANDi) fiber laser are investigated. Our simulations show that, as the relative length of the dispersion fiber increases, the temporal width and the spectral bandwidth of the output pulse for an ANDi fiber laser with fixed total cavity dispersion or fiber length are decreased, while the pulse energy is enhanced and the compressed pulse width is increased.These simulation predictions have been proved by our experimental results. The reason may be that the nonlinear phase shift accumulated in the nonlinear fiber is more than that in the dispersion fiber if they have the same length. 相似文献
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1410 nm波段分布式光纤拉曼增益放大器的研究 总被引:6,自引:2,他引:4
讨论了分布式光纤拉曼增益放大器的工作原理,采用1320nm固体激光器作为抽运源,获得了1410nm波段附近的光放大,在单模GI光纤长度为23km时,初步研究了拉曼放大器增益与光纤作用长度的关系,抽运脉冲峰值功率分别为50W、30W时,光纤的有效作用长度分别为15.5km和10.5km;研究了在不同的光纤有效作用长度时,拉曼放大器增益与抽运功率的关系;从光纤拉曼光谱图估算了光纤拉曼放大器的光谱宽度为50nm或250cm^-1。 相似文献
16.
Hisham Kadhum Hisham Ahmad Fauzi Abas Ghafour Amouzad Mahdiraji Mohd Adzir Mahdi Ahmad Shukri Muhammad Noor 《Optical Review》2012,19(2):64-70
A comprehensive study on the small-signal intensity modulation (IM) characteristics of a fiber grating Fabry-Perot (FGFP)
laser is numerically investigated. The effect of external optical feedback (OFB), temperature, injection current, cavity volume,
nonlinear gain compression factor, and fiber grating (FG) parameters on IM characteristics are presented. The temperature
dependence (TD) of IM is calculated according to the TD of laser cavity parameters instead of using the well-known Parkove
relationship. It has been shown that the optimum external fiber length (L
ext) is 3.1 cm. The optimum range of working temperature for FGFP laser is between 23 to 27 °C. We also show that by increasing
the laser injection current from 10 to 60 mA, the IM peak amplitude decreased from 6.3 to 0.2 dB and the relaxation-oscillation
frequency (ROF) is shifted from 1.2 GHz towards higher frequency of 5.48 GHz. In addition, the AR coating reflectivity and
gain compression factor have no significant effect on the IM. The study indicates that a stable operation and excellent modulation
characteristic can be obtained after optimization process. 相似文献
17.
The output characteristics of a linear cavity Yb-doped double-clad fiber (DCF) laser, including the effects of fiber length, fiber loss, and output mirror reflectivity on laser output power and threshold pump power have been studied theoretically and experimentally. In this paper, the linear cavity of double-clad fiber laser (DCFL) was composed of a pair of fiber Bragg gratings, while the facet of fiber was anti-reflection (AR) coated at 1070nm to erase the Fresnel reflection. Analysis showed that the laser output increases as the reflectivity of the fiber Bragg grating used as the output mirror decreases. At last, under the pump power of 14.4 W, single-mode laser output at 1070 nm was up to 10.8 W, with slope efficiency of 75 %. 相似文献
18.
Fiber laser resonator configurations have been analyzed theoretically on the basis of steady-state rate equations to optimize the laser conversion efficiency. Evolution of the pump- and signal powers and the saturated gain coefficient along the length of the laser medium has been simulated for high- and low-finesse resonators in forward- and backward pumping schemes. The corresponding fiber laser configurations have been setup to verify the results of simulation. Backward pumping configuration in an Yb-doped fiber laser has been found to be the most efficient, and in this configuration a maximum cw output power of 10.75 W in single transverse mode with an optical-to-optical conversion efficiency of 62.5% has been achieved. The laser output spectrum was peaked at 1093 nm with full-width at half-maximum (FWHM) line-width of about 9 nm. In the low-finesse resonator configuration, it has been found that experimental observations differ from theoretical simulation results. In this case, output power from both ends ceases to increase linearly beyond 1.8 W, and starts fluctuating due to the onset of strong random self-pulsing phenomenon. Our investigation shows that a non-uniform steady-state gain along the fiber length facilitates the self-pulsing process. 相似文献
19.
We observed a small-signal gain of Ar2* emission at 126 nm by use of a hollow fiber to guide the high-intensity laser propagation in high-pressure Ar. The small-signal gain coefficient was measured to be 0.05 cm(-1) at 126 nm. Kinetic analysis revealed that the electrons produced by the high-intensity laser through an optical-field-induced ionization process initiated the Ar2* production processes. The increase in the emission intensity was measured to be exp(2.5), with an increase in the fiber length. 相似文献
20.
To date no commercial fiber coupled laser systems have reached the irradiance and pulse energy required for flammable mixtures
ignition. In this work we report preliminary results on the ignition of two-phase mixtures promoted by a laser delivering
pulses through optical fiber. Experiments undertaken on free beam path configurations have allowed identification of the optical
parameters required for laser ignition. The fiber coupled system used is based on a Q-switched nanosecond laser operating
at 1064 nm. The fiber input angle and the focal length have been identified as the most important parameters. We demonstrated
the possibility of delivering nanosecond pulses of 30 mJ focused onto a spot of 200 μm through a solid core optical fiber,
and to promote ignition of n-heptane/air and JP4/air mixtures.
PACS 42.62.-b; 42.81.-i; 47.55.-t; 82.33.Vx 相似文献