1mJ窄线宽掺镱脉冲光纤放大器

1 mJ narrow linewidth Yb-doped pulsed fiber amplifier

通过将固体激光器种子源与光纤放大技术相结合的方式,报道了一个单脉冲能量约为1 mJ,同时窄线宽保持在约0.1 nm的大模场面积的掺镱脉冲光纤放大器。不同于传统固体种子源一级大芯径光纤放大结构,所采用的两级掺镱双包层光纤(YDCF)放大结构空间耦合调节更简单。放大过程中采用了多种非线性效应抑制方法,放大输出光中未出现明显的SBS、SRS等非线性效应,信噪比超过30 dB。放大后平均功率10.07 W,相比0.38 W的种子光提高了14.23 dB。在10 kHz重复频率下,单脉冲能量约1 mJ,输出光脉宽50 ns,放大输出光束质量M^2=3.72。所实现的毫焦量级窄线宽脉冲光纤放大器可运用于激光遥感、激光测量及非线性频率变换等应用领域。

By combining a large mode area(LMA)Yb-doped double cladding fiber(YDCF)amplifier with a solid state seed laser,an fiber amplifier,whose single pulse power was about 1 mJ and narrow linewidth was about 0.1 mJ,was reported.Different from the traditional one-stage fiber amplifer with solid state laser seed source,a two-stage large diameter fiber amplifer was used in the YDCF amplification system.The two-stage fiber amplifer was much simpler in the aspect of coupling the spatial seed light into the fiber.A variety of methods were used to suppress nonlinear effects during the amplification process.Obvious nonlinear effects such as SBS,SRS,were not observed in the output,with the SNR exceeding 30 dB.After YDCF amplification system,the output average power was amplified to10.07 W.Compared to the power of seed,which was about 0.38 W,the output was increased by 14.23 dB.At the pulse repetition rate of 10 kHz,the pulse energy is about 1 mJ,with the pulse width of 50 ns.The beam quality M^2 of the output laser is 3.72.The pulsed fiber amplifier with narrow linewidth and high pulse energy will be very useful in many practical applications,such as laser remote sensing,laser measurement and nonlinear frequency conversion and so on.