Study of All Fiber Passively Q-Switched Pulses Laser

• Main Authors: Shin-An Fan, 范信安
• Other Authors: Chwen-Shell Ho
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/18202805653536288799

碩士 === 中原大學 === 應用物理研究所 === 95 === An all-fiber passive Q-switched pulsed laser has been established and its performance has been investigated. The laser system was configured by using a Samarium (Sm)-doped fiber as saturable absorber, a Yb3+-doped double cladding fiber as the gain medium, and a Bragg-fiber gratings as the optical cavity. In the past, most of the Q-switched fiber lasers are consist of bulky elements that normally invoke sophisticated designs and are usually drawback by incompactness. Here, the conventional crystal saturable absorber was replaced by a Sm-doped fiber, making this pulsed laser as a genuine all-fiber Q-switched laser. In addition, a Yb3+-doped double cladding fiber was also adopted in the system to improve its coupling efficiency and output power. In the preliminary test, a pulse energy of 202 nJ, repetition rate of 50 kHz have been shown. The present optimized results, the pulse width of 0.9μs, and with a peak power of 224.4 mW at center wavelength of 1086.44 nm and a FWHM bandwidth of 1 nm were achieved. The effects of pumping optical source power on the output power, repetition rate, and pulse energy were also investigated. It was found that the higher the pumping power, the higher the output power and pulse energy, but the lower the repetition rate.