Q-switched and mode-locked pulse generation from ytterbium doped fiber

• Main Authors: Kuan-Hao Huang, 黃冠皓
• Other Authors: Ja-Hon Lin
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/4vs5e2

碩士 === 國立臺北科技大學 === 光電工程系研究所 === 104 === In this work, I investigated the Q-switched and mode-locked pulse generation in all-normal dispersion passively mode-locked Yb-doped fiber laser (PML-YDFL) based on the Bi2Se3/Polyvinyl alcohol (PVA) film or fiber-compatible topological insulator saturable absorber (TI-SA). First, we synthesized the Bi2Se3 nano-plates (NPs) via a polyol method and then dissolved the PVA into Bi2Se3 solution to produce the Bi2Se3/PVA solution. Through the drying of the Bi2Se3/PVA solution in standard cell within the oven, the dark and light Bi2Se3/PVA films were produced with high and low transmittance. After insertion the dark Bi2Se3/PVA films into an Yb-doped fiber laser laser (YDFL), the Q-switched pulse can be generated after properly adjusting of the polarization controller. As pump power increased from 105 to 182 mW, the repetition rate of Q-switched pulses was increased from the 86 KHz to 138 KHz. In addition, the mode-locked pulses with 16 MHz repetition rate and the shortest pulsewidth about 380 ps were demonstrate through the light Bi2Se3/PVA film with the pump power at 380 mw. We also fabricate the fiber-compatible TI-SA by depositing the Bi2Se3 NPs onto the fiber end facet. In comparing to the PVA film, the PML-YDFL can be mode locking at lower threshold power and higher slope efficiency. With the pump power at 131 mw, the mode-locked pulses with 13 MHz repetition rate and the shortest pulsewidth about 331 ps were demonstrate through the fiber-compatible TI-SA. Our experimental results indicate that the TI-SA made by the Bi2Se3 can be exploited for the pulsed laser applications.