Chao YANG, Meng CHEN^*, and Gang LI

Institute of Laser Engineering, Beijing University of Technology, Beijing 100124, China

(Received August 23, 2013; Accepted March 3, 2014)

We report on a high-pulse-energy 888 nm diode-pumped passively mode-locked TEM₀₀ Nd:YVO₄ oscillator without spatial hole burning (SHB) effect in active medium. At a pump power of 40 W, the oscillator produced pulse energy up to 270 nJ at a repetition rate of 50 MHz, corresponding to average power of 13.5 W with 34% optical-to-optical efficiency. To the best of our knowledge, it is the highest pulse energy obtained at the same pump power. The pulse duration produced varied from 16 to 59 ps. By varying the pump power, we observed a pulse duration ranging from 52 to 59 ps while the time-bandwidth product remained 0.88, and the factors that affect the pulse duration were also discussed. Meanwhile, a novel method of adjusting output coupling (OC) was introduced, which can simplify the structure of laser.

Key words: laser techniques, solid-state, mode-locking, picoseconds, neodymium

^*E-mail address: chenmeng@bjut.edu.cn