脉冲变压器与陡化开关结合的方式是产生纳秒脉冲较为成熟的方式, 采用这种方式, 研制了一种基于空芯Tesla变压器和陡化开关的紧凑高压重复频率纳秒脉冲源。该脉冲源主要由重复频率充电模块、Tesla变压器和陡化开关三部分组成, 重复频率充电模块主要通过晶闸管的时序配合实现, Tesla变压器为脉冲源装置系统的核心及主升压模块, 陡化开关是一个三电极自击穿型气体开关, 用于将变压器次级输出的电压陡化成纳秒快脉冲波形, 对该重复频率脉冲源以上各部分进行了详细的设计和测试。实验结果表明, 该脉冲源可以在6 kΩ的负载电阻上输出幅值100 kV、上升沿约为30 ns、最高频率可达500 Hz的高压纳秒脉冲。

以被动调Q的固体薄片激光器作为种子光源，以中心波长976 nm的半导体激光器为抽运源，通过端面抽运耦合，搭建了窄脉宽双包层掺镱光纤放大器。实验研究了前向、后向端面抽运方式对窄脉宽双包层掺镱光纤放大器的输出平均功率、激光光谱、脉冲宽度等特性的影响，并进行分析讨论。结果表明,采用后向抽运方式，窄脉宽双包层掺镱光纤放大器，获得了平均功率为9.3 W的放大激光输出，重复频率为10 kHz，脉冲宽度为450 ps，峰值功率大于2 MW。

研制了输出功率达17.3 W的单频保偏掺镱光纤放大器,并对其输出激光特性进行了实验研究。该光纤放大系统以Nd:罽VO4单频固态激光器为种子源,以保偏光纤为增益介质,通过二级光纤放大,获得了波长为1064 nm的单频线偏振激光输出,输出激光功率达17.3 W。功率放大级光纤放大器的斜率效率为62.8%,光光转换效率为57.6%,偏振消光比为24.3 dB。

Laser-diode pumped Q-switched ytterbium-doped fiber laser is studied experimentally by controlling the switching time of acousto-optic modulator (AOM). The characteristics of Q-switched pulses with different rise time of AOM regulated by the laser beam size along the window of AOM are presented. Meanwhile, the behaviors of Q-switched pulses are achieved by regulating the switching time of AOM. The single-repetition-rate and half-repetition-rate phenomena are described and discussed. The experimental results confirm that the fiber laser with lower level inversion population can be more easily operated for half-repetition-rate generation.

利用倍频Nd∶YAG激光器使玻璃基底上沉积的非晶硅薄膜成功实现了晶化。YAG激光器的倍频绿光经蝇眼透镜阵列整形后得到一光强均匀分布的平顶光束, 并用此光束对非晶硅薄膜进行扫描晶化处理。分别测量了激光晶化前后薄膜的拉曼谱和表面形貌。测量结果表明, 非晶硅实现了到多晶硅的相变, 且晶化处理后表面起伏度明显增大。根据拉曼谱的数据计算了不同激光能量密度下薄膜的粒度大小和结晶度。结果表明, 在一定能量密度(400～850 mJ/cm2)范围内, 结晶膜的晶粒粒度和结晶度随激光能量密度升高而增大。然而能量密度大于1000 mJ/cm2后, 检测不到明显的多晶硅特征峰。激光能量密度在850 mJ/cm2左右可得到最佳晶化效果。

A pulsed master-oscillator fiber power amplifier system with near diffraction-limited output by use of China-made large-mode-area fiber and a (2+1)×1 multimode combiner is reported. The effect of the seed power on the amplification performance is found. For the seed power, there exists a range within which the pulsed fiber amplifier can operate safely and reliably at a certain pump power. With the seed average power of 70 mW, the amplification performances of the fiber amplifier are investigated.

A simple laser-diode pumped acoustic-optic Q-switched fiber laser is reported by using China-made large-mode-area ytterbium-doped fiber. Q-switched pulses with a beam quality factor of M2 about 2 and several hundred nanoseconds pulse duration are achieved at the repetition rate of 1-50 kHz. When the repetition rate is 1 kHz, the pulse energy is 0.93 mJ with the pulse duration of 132 ns. Meanwhile, the profile of laser pulses shows some mode-locking phenomena, the mechanism of the phenomena is discussed.

Phase locking for two ytterbium-doped large-core fiber lasers has been demonstrated by using a self-imaging confocal resonator with a spatial filter. Steady high-contrast interference stripes are observed. The visibilities of coherent and incoherent stripes are 59% and 6%, respectively. The measured width of the central strip is in good agreement with the calculated result. For in-phase mode, the output power of the phase-locked fiber laser array is up to 113 W and corresponding slope efficiency is 38.5%.

A narrow-linewidth master-oscillator fiber power amplifier system was presented, in which an ultrastable, continuous-wave, single-frequency laser was adopted as the master oscillator and a China-made Yb-doped large-mode-area fiber was used as the power amplifier medium. The system generates single-frequency radiation up to 7.3 W at 1064-nm wavelength with 39% slope efficiency and 26% optical-optical power conversion efficiency. The spectral characteristics as well as the suppression of amplified spontaneous emission were discussed in detail.

A master-oscillator fiber power amplifier (MOPA) system is presented, which consists of a single mode laser as the master oscillator and an Yb^{3+}$-doped large-mode-area double-clad fiber as the power amplifier. The system emits up to 6 W of amplified radiation at a wavelength of 1064 nm. The slope efficiency and extracted pulse energy as a function of pulse repetition rate are analyzed.