All-Fiber Passively Q-Switched Laser Based on Tm3+-Doped Tellurite Fiber

We report all-fiber passively Q-switched Tm
³⁺
-doped tellurite fiber lasers. The composite tellurite fiber is specially designed to improve the mechanical strength. Both carbon nanotubes (CNTs) and semiconductor saturable absorber mirror (SESAM) are inserted separately into the laser cavities as SAs to demonstrate a fiber-integrated setup. In a short, 9-cm tellurite fiber, 1.86-
$\mu \text{m}$
-pulsed lasers without self-mode-locking effect are demonstrated by in-band pumping at 1.59
$\mu \text{m}$
. An average power of 84 mW is obtained in CNT-pulsed laser with 860-ns duration, whereas in SESAM-pulsed laser, the average power reaches 21 mW with 516-ns pulsewidth.