介绍了全正色散掺镱锁模光纤激光种子源及光纤放大器。系统包括利用非线性偏振旋转锁模的种子源和正向抽运的放大器两部分。实验中得到了平均功率为125 m W的锁模激光种子源,其输出脉宽约为4 ps,重复频率为88.3 MHz。经过放大器放大后,平均功率达到3.5 W,脉宽为7.2 ps,单脉冲能量为39.64 n J。
A Q-switched Er-doped all-fiber laser, based on a single-walled carbon nanotube saturable absorber （SA） is constructed. The SA with a modulation depth of 8% is prepared using a special chemical-corrosion method. Furthermore, the SA is introduced to an Er-doped all-fiber laser, and Q-switching is obtained successfully. The repetition rate of the Q-switched laser can be tuned continuously from 128 to 278 kHz with pulse widths from 1.92 las to 488 ns. The maximum output power is 13.1 mW.
We present a compact passively mode-locked semiconductor disk laser at 1045 nm. The gain chip without any post processing consists of 16 compressively strained In Ga As symmetrical step quantum wells in the active region. 3-GHz repetition rate, 4.9-ps pulse duration, and 30-mW average output power are obtained with 1.4 W of 808-nm incident pump power. The temperature stability of the laser is demonstrated to have an ideal shift rate of 0.035 nm/K of the lasing wavelength.
A mode locked Er-doped fiber laser based on a single-wall carbon nanotube saturable absorber is demonstrated. A high quality single-wall carbon nanotubes （SWCNTs） absorber film is fabricated by a polymer composite. The pulse duration is 488 fs with 9.6-nm spectral width at the center of 1564 nm. The repetition rate is 30.4 MHz. The maximum output power is 3 mW. And the single pulse energy is 0.1 nJ.
Self-Q-switching is observed in a bulk Yb：KGd（WO4）2 oscillator without any additional modulating elements. The output power reaches 434.4 mW at a pump power of 13.67 W, corresponding to pulse repetition rate of 125 kHz and a pulse duration of 2.5μs, respectively, The mechanism of self-pulse formation is explained by the re-absorption effect of the Yb^3＋ ion in Yb：KGd（WO4）2.
We demonstrate the first use of single layer graphene for compressing self-Q-switching pulses in semiconductor disk lasers. The gain region of the semiconductor disk laser used InGaAs quantum wells with a central wavelength of 1030 nm. Due to self saturable absorption of the quantum wells, the disk laser emitted at the self-Q-switching state with a pulse width of 13 μs. By introducing the single layer graphene as a saturable absorber into the V-shaped laser cavity, the pulse width of the self-pulse was compressed to 2 μs with a lower pump power of 300 mW. As the pump power was increased, multiple pulses with the pulse width of 1.8 μs appeared. The compression factor was about 7.2.
