Resonantly pumped 1645 μm high repetition rate Er:YAG laser Q-switched by a graphene as a saturable absorber

Abstract

A fiber laser resonantly pumped 1.645 μm passively Q-switched Er:YAG laser is reported. Graphene on a silicon carbide was used as the saturable absorber for the Q-switching. The pulse energy of the 1.645 μm Q-switched Er:YAG laser was 7.05 μJ, with a pulse repetition rate of 35.6 kHz and an average output power of 251 mW.

High Power Continuous-Wave and Graphene Q-switched Operation of Er:YAG Ceramic Lasers at ~1.6 ㎛

“…Since first experimental demonstration of mode-locking in erbium fiber laser with graphene as a saturable absorber (SA) [11], graphene has also been successfully employed as SA in Q-switched or mode-locked solid-state lasers with various rare-earth elements doped gain media, e.g. Nd:YAG ceramic [12], Tm:YAG [13], Tm:CLNGG [14] and Er:YAG single crystals [15] etc. and the broadband saturable absorption characterization has been confirmed.…”

Topological Insulator: <formula formulatype="inline"><tex Notation="TeX">$\hbox{Bi}_{2}\hbox{Te}_{3}$ </tex></formula> Saturable Absorber for the Passive Q-Switching Operation of an in-Band Pumped 1645-nm Er:YAG Ceramic Laser

“…To establish the Q-switching (Q-S) operation at 1.645 m, the laser cavity must be incorporated with an intensity modulation component, namely, an electrooptic or an acoustic-optical switcher by Shen et al [5], Wang et al [6], and Moskalev et al [7], in which, however, the intensity modulation component shows the disadvantage of being expensive, lossy, and bulky. To overcome those drawbacks from those crystal-based modulators, Gao et al reported the first passive Q-S operation at 1.645 m with a single pulse energy of 7.05 J by a graphene saturable absorber [8]. Since the first demonstration of passive mode locking by a graphene saturable absorber [9], graphene had already been widely recognized as a passive Q-switcher and a mode locker for various wavelengths in either fiber lasers [10]- [12] or solid-state lasers [8], [13]- [19].…”

“…To overcome those drawbacks from those crystal-based modulators, Gao et al reported the first passive Q-S operation at 1.645 m with a single pulse energy of 7.05 J by a graphene saturable absorber [8]. Since the first demonstration of passive mode locking by a graphene saturable absorber [9], graphene had already been widely recognized as a passive Q-switcher and a mode locker for various wavelengths in either fiber lasers [10]- [12] or solid-state lasers [8], [13]- [19]. Due to the linear energy band structure in graphene, it could absorb a wide spectrum of photons, and, therefore, operate as a broad-band saturable absorber, which accounts for the passive Q-S operation at 1.645 m. However, in addition to graphene, saturable absorbers operating at 1.645 m are still hardly available, and correspondingly, the search for new types of saturable absorbers, operating at this particular wavelength, is highly encouraged.…”

Mode-locked 2-μm wavelength fiber laser using a graphene-saturable absorber

“…Graphenebased SAMs have been fabricated via (1) dispersion of graphene in a solution with poly(methyl methacrylate) 20 and polyvinyl-alcohol, 21 (2) liquid-phase exfoliation of small area (∼20 μm) flakes, 8,22,23 or (3) chemical vapor deposition on copper foils and transferral to a mirror. 3,10 Until now, epitaxially grown graphene on silicon carbide (SiC) was used as a saturable absorber only in Q-switched lasers, 9,19,24,25 and not in mode-locked lasers. Here, we report a graphene SAM fabricated using large-area epitaxially grown graphene on SiC and transferred by a unique dry transfer process to an Ag mirror.…”