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1.
Characteristics of a Q-switched multicore photonic crystal fiber laser with a very large mode field area 总被引:2,自引:0,他引:2
We model and characterize the behavior of a Q-switched fiber laser. The fiber is a doped multicore photonic crystal fiber having six cores in a ring-type geometry. The fiber laser is Q-switched using an intracavity acousto-optic modulator. Using a mode filtering technique in the far field, a mode very close to the fundamental in-phase supermode is obtained with a mode field area of 4200 microm(2) and a divergence of 9 mrad. Pulses with energies of up to 2.2 mJ and durations of 26 ns (limited by end facet damage) at a repetition rate of 10 kHz are obtained. 相似文献
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以七芯光纤激光器为例,提出一种提高多芯光纤激光器总输出光功率中共相位模式所占比例的方法,即把多芯光纤激光器作为种子光源,输出信号光再经过多芯光纤放大器进行放大。基于速率方程组对激光器和放大器中的模式竞争进行了数值分析。计算表明:激光器输出端与放大器输入端之间距离存在一个最佳值,以使得放大器输出信号中低阶模式功率占总输出功率的比例最低,可以下降到小于1%。研究表明:级联放大系统可以有效增强共相位模式同时抑制低阶模式,比传统的塔耳博特腔激光器具有更好的光束质量。 相似文献
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Li L Schülzgen A Chen S Temyanko VL Moloney JV Peyghambarian N 《Optics letters》2006,31(17):2577-2579
We report a compact multicore fiber laser that utilizes an all-fiber approach for phase locking and in-phase supermode selection. By splicing passive coreless fibers of controlled lengths to both ends of an active 19-core fiber, we demonstrate that the fundamental in-phase supermode can be selectively excited with a completely monolithic fiber device, instead of conventional free-space and bulk optics, to achieve phase-locked operation for a multiemitter laser device. 相似文献
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Chun-can Wang Ling-xian Gong Jue-ling Li Fan Zhang Shui-sheng Jian 《Optics Communications》2011,284(18):4215-3941
Two passive cores with elliptical air holes are introduced in the cladding of the active multicore fiber. The birefringence induced by the elliptical air holes lifts the degeneracy between two orthogonal in-phase supermodes, through the coupling between the passive and the active cores. For the proposed multicore fiber with an appropriate choice of the design parameters, the x-polarized in-phase supermode has more mode power in the active cores compared with the other supermodes. That in turn favors competition compared to the other supermodes with the low power density in the active cores. The numerical results show that the multicore fiber lasers can output a pure x-polarized in-phase supermode without using other mode-selective elements. 相似文献
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B. M. Shalaby V. Kermène D. Pagnoux A. Desfarges-Berthelemot A. Barthélémy A. Popp M. Abdou Ahmed A. Voss T. Graf 《Applied physics. B, Lasers and optics》2010,100(4):859-864
We propose a new method to control the mode combination at the output of a 19-core fiber laser in order to produce a bright beam with uniform phase. The technique is based on both the selective excitation of the amplifying multicore fiber and on an intra-cavity angular filtering at the output. The excitation of the fundamental in-phase supermode of the 19-core fiber was demonstrated, resulting in the emission of a single-mode beam with M 2 limited to 1.21. 相似文献
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We propose a novel multicore fiber design strategy for obtaining a flat in-phase supermode that optimizes utilization of the active medium inversion in the multiple cores. The spatially flat supermode is achieved by engineering the fiber so that the total mutual coupling between neighboring active cores is equal. Different designs suitable for different fabrication processes, such as stack-and-draw and drilling, are proposed. An important improvement over previous methods is the design simplicity and better tolerance to perturbations. 相似文献
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B. M. Shalaby V. Kermene D. Pagnoux A. Desfarges-Berthelemot A. Barthélémy 《Applied physics. B, Lasers and optics》2011,105(2):213-217
We report on a fiber laser configuration, emitting two phase-locked and single mode beams at the output of two multicore fibers.
The passive technique is based both on the selective excitation of the only in-phase supermodes of the multicore fibers and
on an intra-cavity angular filtering of the emitted beams to provide phase control. As a proof of principle, we experimentally
demonstrate the coherent combining of the fundamental in-phase supermodes of two parallel 7-cores fibers. 相似文献
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We reported on the supermode selection of total-internal-reflection photonic crystal fibers (PCFs) with linearly and circularly distributed multicores. The supermode characteristics were investigated using a full-vector finite-element method (FEM). The near and far-field patterns of supermodes supported by the multicore photonic crystal fiber were presented. A Talbot cavity was employed to select the wanted supermode. 相似文献
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We present a 10-GHz hybrid actively and passively mode-locked fiber ring laser with a dispersion im-balanced nonlinear loop mirror (DI-NOLM), whose nonlinear switching characteristic can make the laser operate at additive pulse modelocking (APM) mode or additive pulse limiting (APL) mode. When the laser operated at APM, 5.45 ps of transform-limited pulse series were obtained. When the laser was biased at APL region, supermode noise was suppressed and the laser output was more stable. 相似文献
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Fang XH Hu ML Huang LL Chai L Dai NL Li JY Tashchilina AY Zheltikov AM Wang CY 《Optics letters》2012,37(12):2292-2294
High-power supercontinuum spanning over more than an octave was generated using a high power femtosecond fiber laser amplifier and a multicore nonlinear photonic crystal fiber (PCF). Long multicore PCFs (as long as 20 m in our experiments) are shown to enable supercontinuum generation in an isolated fundamental supermode, with the manifold of other PCF modes suppressed due to the strong evanescent fields coupling between the cores, providing a robust 5.4 W coherent supercontinuum output with a high spatial and spectral quality within the range of wavelengths from 500 to 1700 nm. 相似文献
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A large mode area multicore photonic crystal fiber with a flattened fundamental mode is proposed in this paper. Another two kinds of single core fibers are also presented as comparison. The modal characteristics such as effective mode area and confinement loss are investigated using the finite element method. Numerical results show that a combination of flattened fundamental mode, large mode area and ultralow loss is obtained in the multicore fiber by introducing higher refractive index in the core region. 相似文献
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It is shown that the interference between amplified spontaneous emission into the nonlasing supermode and the laser field of a semiconductor laser array causes spatial hole burning, which couples the dynamics of the amplified spontaneous emission with the laser field. In particular, phase locking between the amplified spontaneous emission and the lasing mode leads to the formation of a spectral triplet composed of in-phase relaxation oscillation sidebands and an out-of-phase line at the lasing frequency. 相似文献
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The phase-noise characteristics of a harmonically mode-locked fiber laser are investigated with a new measurement technique called phase-encoded optical sampling. A polarization-maintaining ring laser is mode locked by use of the short-pulse electrical output of a resonant-tunneling diode oscillator, enabling it to produce 30-ps pulses at a 208-MHz repetition rate. The interferometric phase-encoded sampling technique provides 60-dB suppression of amplitude-jitter noise and allows supermode phase noise to be observed and quantified. The white-noise pulse-to-pulse timing jitter and the rms supermode timing jitter of the laser are measured to be less than 50 and 70 fs, respectively. 相似文献
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Low-threshold 115-GHz continuous-wave modulational-instability erbium-doped fiber laser 总被引:3,自引:0,他引:3
A pulse train with a repetition rate of 115GHz was obtained at 1.55 microm from a continuous-wave modulational-instability erbium-doped fiber laser. This laser has a Fabry-Perot filter whose free spectral range is set at 115GHz, corresponding to the modulational-instability gain peak. This filter enables us to initiate modulational instability easily with a low threshold and produce a stable, continuous-wave pulse train. The stability of the pulse train is greatly improved by suppression of supermode noise with a combination of self-phase modulation and a narrow-band optical filter. 相似文献
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从理论和实验上对二极管激光阵列在Talbot外腔中的锁相进行了研究。在同相模和异相模近场分布的基础上,利用1维情况下的菲涅耳衍射公式计算了其远场分布。根据同相模和异相模在Talbot腔中的分布特性,采用1/2 Talbot腔并将外腔镜倾斜一个角度a的方法既能选择同相模,又能使模式的功率损耗最小。二极管激光阵列芯片采用CD金刚石材料,“三明治”结构对其进行封装,明显地减小了阵列的“smile”效应。在实验中实现了二极管激光阵列同相模的锁相输出,远场单瓣模的半高全宽为0.11 mm。 相似文献
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Zhang G. Zhang Q. Shen Y. L. Zhou Q. L. Hu L. L. Qiu J. R. Chen D. P. 《Laser Physics》2011,21(2):410-413
Two compact fiber lasers based on the gain medium of Nd-doped phosphate glass multicore fiber (MCF), of length no more than
10 cm, have been demonstrated experimentally for the first time. A stable phase-locked laser beam at 1055 nm emitted from
a three-core fiber that is 8.5 cm in length has been achieved, with a maximum output power of 20 mW. The properties of similar
seven-core fiber laser also have been investigated. 相似文献
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An actively mode-locked fiber laser is demonstrated, for the first time to our knowledge, by modulation of a saturable-absorber mirror with the light used simultaneously for pumping the gain fiber. Stabilization of a harmonically passive mode-locked fiber laser that generates soliton pulses of 550-fs duration is obtained with this technique. The results indicate a reduction of supermode suppression by more than 55 dB. The timing jitter is improved by 9 dB. 相似文献