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In this paper, a new saturable absorber (SA) based on Lanthanum Hexaboride (LaB 6) is used to produce Q-switched and mode-locked laser pulses. In constructing the SA, the prepared LaB 6 powder is dispersed in polyvinyl alcohol (PVA) solution before the mixture is dried to form a thin film. A small piece of the film is placed between two fiber ferrules to form a LaB 6 PVA SA and added to a laser cavity of an erbium-doped fiber laser (EDFL) to produce Q-switched and mode-locked pulses. The Q-switched laser operates at 1531 nm. The pulse width of the pulses can be varied between 4.32 to 2.46 μ s with a corresponding repetition rate of 62.0 to 89.6 kHz when the pump power is increased from 45.4 to 97.6 mW. At the maximum output power of 4.31 mW, the highest pulse energy of 48.1 nJ was obtained. A passively mode locked EDFL was also successfully realized with LaB 6 SA by adding 100 m long single mode fiber inside the cavity. A stable mode-locked laser operating at 1559.1 nm was achieved at the threshold pump power of 102.8 mW with a pulse rate of 1.88 MHz. The pulse energy of 5.6 nJ and output power of 10.54 mW were obtained at a maximum pump power of 144.6 mW. To the best of our knowledge, this is the first demonstration of utilizing LaB 6 material as SA to produce pulses in the 1.5 μ m region. • Lanthanum Hexaboride (LaB 6) as saturable absorber to produce Q-switched and mode-locked pulses. • The prepared LaB6 powder is dispersed in polyvinyl alcohol (PVA) solution. • The SA has a modulation depth of 4.2%. • The Q-switched and mode-locked laser operated at 1531 nm and 1559.1 nm, respectively. • The mode-locked pulse has 157.8 ns pulse width and 1.88 MHz repetition rate. [ABSTRACT FROM AUTHOR]