title: Efficient graphene Q switching and mode locking of 1.34 μm neodymium lasers.
abstract: We demonstrate that few-layered graphene sheets used as a saturable absorber can provide efficient Q-switching and mode-locking modulation in 1.34 μm Nd:GdVO(4) bulk lasers. The minimum Q-switched pulses were 450 ns for 260 mW average power, 43 kHz repetition rate, and 2.5 μJ pulse energy. For the mode-locked laser, an average power of 1.29 W was achieved with 11 ps pulse duration and 13 nJ pulse energy. To our knowledge, this average power is the highest yet obtained from a graphene mode-locked laser, and the corresponding optical-optical efficiency of 23% is the best result among 1.3 μm neodymium mode-locked lasers. The quality factor M(2) of the Q-switched beam was 1.4 and 1.6 in the horizontal and longitudinal planes, respectively, and the M(2) of the mode-locked beam reached 1.1 and 1.0. These results clearly indicate the advantages of few-layered graphene as a saturable absorber.
authors: State Key Laboratory of Crystal Materials, Shandong University, 250100 Jinan, China.
authors: Jin-Long
authors: JL
authors: Xu
authors: Xian-Lei
authors: XL
authors: Li
authors: Jing-Liang
authors: JL
authors: He
authors: Xiao-Peng
authors: XP
authors: Hao
authors: Ying
authors: Y
authors: Yang
authors: Yong-Zhong
authors: YZ
authors: Wu
authors: Shan-De
authors: SD
authors: Liu
authors: Bai-Tao
authors: BT
authors: Zhang