AUTHOR=Zheng Le , Sun Fanxi , Zhou Hongrong , Gao Ang , Liu Wenshu , Wang Dongsheng , Wei Chen , Liu Yong 

TITLE=MIL-68(Al) and MIL-68(Fe) as broadband optical modulators for Q-switching fiber lasers operating at 2 and 2.9 μm

JOURNAL=Frontiers in Physics

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2022.1066166

DOI=10.3389/fphy.2022.1066166

ISSN=2296-424X

ABSTRACT=<p>We investigated 2 and 2.9 μm mid-infrared fiber lasers passively Q-switched by MIL-68(Al) and MIL-68(Fe), which were fabricated <italic>via</italic> the hydrothermal method. The modulation depth of MIL-68(Al) was found to be 9.12% at 1.99 μm. And the modulation depths of MIL-68(Fe) were found to be 18.89% and 15.79% at 1.99 μm and 2.87 μm, respectively. We report Q-switching pulse generation in both Tm<sup>3+</sup>-doped and Ho<sup>3+</sup>/Pr<sup>3+</sup> co-doped fiber lasers by using the as-prepared MIL-68 (M, M = Al<sup>3+</sup>, Fe<sup>3+</sup>) as SAs. The center wavelengths were at 1.99 μm and 2.87 μm, respectively. These results indicate that MIL-68(M) has wideband nonlinear optical properties and promising application prospects in the field of optical modulators at 2- and 2.9-μm mid-infrared waveband. Work clearly accessible to a broad readership.</p>