Directly Blue Diode-Pumped Green Self-Q-Switched Ho3+-Doped Fluoride All-Fiber Laser at ∼550 nm

Abstract

We successfully demonstrate a blue diode-pumped green single-wavelength self-Q-switched Ho <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> :ZrF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> -BaF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -LaF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> -AlF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> -NaF (Ho:ZBLAN) all-fiber laser emitting at ~550 nm. Such a green laser, being a very simple device, consists of a 15-cm-long Ho:ZBLAN fiber and a pair of fiber input/output mirrors. The Ho:ZBLAN fiber not only acts as a gain medium but also works as a saturable absorber (SA). The modulation mechanism is induced by the ground-state reabsorption effect in an ineffectively pumped section of the active fiber. Stable Q-switching pulses are characterized by a 889 ns of minimum pulse duration and a 264 nJ of maximum energy pulse at a repetition rate of 67.25 kHz. We believe that this work could provide an appreciable alternative for next generation of pulsed green laser source, which finds the applications in the medical diagnosis, optical imaging, and industrial manufacturing.