Indium Tin Oxide Nanowire Arrays as a Saturable Absorber for Mid-Infrared Er:Ca0.8Sr0.2F2 Laser

Abstract

We demonstrated a passively Q-switched Er:Ca0.8Sr0.2F2 laser with indium tin oxide nanowire arrays as an optical modulator in the mid-infrared region. In the Q-switched regime, the maximum output power of 58 mW with a slope efficiency of 18.3% was acquired. Meanwhile, the minimum pulse duration and highest repetition rate of the stable pulse trains were 490 ns and 17.09 kHz, corresponding to single pulse energy of 3.4 μJ and peak power of 6.93 W, respectively. To the best of our knowledge it was the first time that indium tin oxide nanowire arrays were employed as a saturable absorber to make pulse lasers carried out at 2.8 μm. The experimental data show that indium tin oxide nanowire arrays can be employed as a competitive candidate for saturable absorber in the field of mid-infrared solid-state lasers.

Mid-infrared lightly Er3+-doped CaF2 laser under acousto–optical modulation

“…The Q-switching is a key method to acquire pulsed laser with high energy, for which different techniques have been explored. [18][19][20] Compared with active Q-switching, passive Q-switching largely depends on saturable absorbers (SAs) whose modulated parameters are beyond manual control, resulting in low pulse energy and unstable repetition rate. Active Q-switching has been done through diverse types of mechanical devices, containing rotating mirrors, prisms, electro-optical (EO) crystals, [21,22] and acousto-optical (AO) crystals.…”