Dual-wavelength stable nanosecond pulses generation from cladding-pumped fiber laser

In this paper, the generation of dual-wavelength stable nanosecond pulses by a laser diode pumped Yb-doped double-clad fiber laser is presented. In the experiment, the fiber laser with two-mirror cavity is approved which operates in a self-Q-switching regime. The Q-switching mechanism is based on stimulated Brillouin scattering (SBS). When the pump power achieves the SBS threshold, the fiber laser changes from the start resonator to the SBS resonator. With different reflectivities of the second mirror, stable dual-wavelength pulses with the pulse width range from 10 ns to less than 2 ns are obtained. The result was explained theoretically by birefringency (including stochastic birefringency and bend birefringency).     

可调谐的调Q掺Yb3+双包层光纤激光器

利用双包层光纤中的受激布里渊散射和声光调Q器件,对掺Yb³⁺双包层光纤激光器进行了混合调Q的实验研究.在连续泵浦状态下,当入纤泵浦功率为1.24W时,在1080～1119nm的可调谐范围内,在国内首次获得了输出脉冲宽度小于6ns,重复频率1.5 kHz,脉冲能量高于80μJ,峰值功率高于13.3kW稳定调Q光纤激光器的脉冲输出.经计算,实验结果和理论计算值符合得很好.     

包层泵浦全光纤调Q激光器

本文研究了包层泵浦全光纤调Q激光器。掺Yb光纤为增益介质，光纤光栅和光纤的垂直端面作为腔镜，利用光纤中的受激布里渊散射和光纤干涉环实现了较稳定的自调Q脉冲输出。在连续泵浦方式下得到了脉宽3.6ns、周期约25μs、峰值功率600W的光脉冲。     

周期极化铌酸锂晶体的红外光谱测量分析

对周期极化非线性品体的光参量振荡器实现连续调谐输出的条件进行了理论模拟和分析,并且针对基于多周期的掺镁铌酸锂晶体光参量振荡器进行了实验研究,在掺镁铌酸锂晶体内制作了6个等间隔的晶畴区,其间距为0.5 μm,极化周期范围为29.0～31.5 μm.在室温下采用LD端面抽运的声光调Q Nd:YVO4激光器作泵浦源,实现了PPMgLN光参量振荡器的信号光在1449.7～1665.0 nm、闲频光在3 989.2～2 946.0 nm范围内的调谐输出,其最低激射阈值为108.0 mW、最高激射阈值为149.2 mW.当泵浦功率为649 mW时,获得了信号光最高为118.5 mW的输出,其光-光转换效率为18.26%;闲频光最高输出为46.6 mW,其光一光转换效率为7.18%.以上参数均接近实用化水平.而且,这两个波段的光源分别在整个光纤通信的S+C+L波段和大气层透射窗口范围,具有十分重要的应用前景.     

Fibre-Format Photonic Source Based on Efficient Frequency Doubling of Continuous-Wave Erbium-Fibre Laser Amplifier

We demonstrate a compact photonic device based on efficient and wavelength-tunable doubling of an all fibreformat source. Quasi-phase-matched second-harmonic generation in periodically poled lithium niobate is used to generate 90.6 m W at 775.9 nm with a single-pass conversion efficiency of 14.7%. A t uning bandwidth of 2.1 nm and a tuning temperature range of 150.6 ± 1.7℃ can be achieved. The Er-doped seed fibre source is amplified by a clad-pumped Er^3＋/Yb^3＋-codoped fibre laser with a high output power up to 2.18 W over a tunable wavelength range from 1535nm to 1570nm.     

紧凑型窄线宽分布反馈光纤激光器

 在铒/镱共掺杂有源光纤上直接刻蚀光栅,制成一台紧凑型非对称π相移分布反馈光纤激光器。光栅总长度约50 mm,最佳相移位置在29 mm处,最佳耦合系数为150 m^-1。采用980 nm激光二极管同向泵浦,当最大泵浦功率为200 mW时,在1 550.94 nm处实现约10 mW激光输出,线宽小于0.05 nm,阈值约35 mW,斜率效率为6.06%,总光 光转换效率为5%,基本满足长距离光通信系统光源功率实用化的要求。     

激光精密刻蚀技术在硅太阳电池制备工艺中的应用

依据光学谐振腔的图解分析与设计方法,对以Nd:YAG固体激光器作光源的激光切割机进行了设计改进,实现了高亮度激光输出.并利用该设备对硅太阳电池进行了激光精密切割试验,使埋栅太阳电池电极槽达到了平均宽度为150±5 μm,槽深100±10 μm的设计指标.在发射结卷包太阳电池所用的硅衬底片上进行激光精密穿孔,目前最小孔径为20 μm.通过应用激光精密刻蚀技术,现将埋栅太阳电池光电转换效率提高到了21%,接近该领域的世界先进水平.     

Pulse Evolution Characteristics in Self-Similar Mode-locked Fibre Laser

A self-similar mode locked fibre laser is studied based on a numerical model. By introducing a dimensionless factor k to characterize the pulse shape, the self-similar pulse evolution, formation and the temporal and spectral shape changes due to the elements in the cavity are investigated throughout the laser cavity. The results show that in the self-similar mode locked fibre laser, self-similar pulse is first formed in the single-mode fibre, which is then amplified in the gain fibre. Gain bandwidth has a small influence on pulse shape, so high energy self-similar pulse can be obtained after amplification. Because net cavity dispersion directly influences the pulse width as well as peak power after compression by a pair of gratings, which can determine the pulse self-similar evolution, it is very important to control the net cavity dispersion to a certain range to obtain self-similar pulses.     

Different operation states of soliton pulses in an erbium-doped fibre ring laser

We report on the experimental observation of soliton pulses in an erbium doped fibre ring laser. The passive mode-locking is achieved using the nonlinear polarization rotation technique. By adjusting the pump power and the intracavity polarization controllers, a normal soliton, a stable 8th harmonic mode-locked pulse and a noise-like pulse have been observed in our laser. The experimental results revealed that the noise-like pulse is not suitable for the optical telecommunication, and in order to obtain the stable harmonic mode-locked soliton, a strong unstable CW laser field is necessary to mediate global soliton interaction. The formation mechanism of the harmonic mode-locked pulse has also been analysed.     

L波段可调谐线形腔Er/Yb共掺双包层光纤激光器

报道了一种结构简单、工作在L波段、可调谐的线形腔Er/Yb共掺双包层光纤激光器.利用由两段高双折射光纤和两个偏振控制器构成的环镜滤波器对激光器进行调谐，使调谐范围达到34 nm，功率起伏小于±0.2 dB.用976 nm多模LD泵浦Er/Yb共掺双包层光纤产生的ASE作为二次泵源，对未泵浦的一段光纤进行泵浦，使腔内Er/Yb共掺光纤的增益谱移到L波段;多个泵浦源同时对Er/Yb共掺双包层光纤进行侧向泵浦，使激光器输出功率超过了200 mW.