Semiconductor saturable absorber mirror passively Q-switched fiber laser near 2 μm

Abstract

A passively Q-switched fiber laser near 2 μm is achieved with a semiconductor saturable absorber mirror (SESAM) as a saturable absorber. Stable Q-switched pulses are generated from an extremely compact setup with a central wavelength of 1958.2 nm. Under the bidirectional pump configuration, the repetition rate of the fiber laser can be widely tuned from 20 to 80 kHz by increasing the pump power at the same time the pulse width decreases from 1 μs to 490 ns. When the incident pump power is 1.3 W, the average output power, the pulse repetition rate, the pulse width, and the highest single pulse energy are 91 mW, 80 kHz, 490 ns, and 1.14 μJ, respectively. To further optimize the system configuration, the pulse width can be reduced to 362 ns when the cavity length is reduced.

High-energy, tunable-wavelengths, Q-switched pulse laser

“…Since the NPR Q-switched laser was unstable against environmental perturbations, only slightly above 10 dB signal-to-noise ratio was observed in their experiment. Q-switched fiber lasers incorporating a real passive saturable absorber (SA), such as a semiconductor saturable absorber mirror (SESAM) [13,14] or carbon nanotubes (CNTs) [8,15,16] have been proposed. A 1.53 mm all-fiber passively Q-switched laser with 0.1 mJ pulse energy based on a SESAM has been reported in [13].…”

Delivering dispersion-managed soliton and Q-switched pulse in fiber laser based on graphene and nonlinear optical loop mirror

“…Q-switched pulse fiber laser and mode-locked pulse fiber laser are the most commonly pulse fiber lasers. There are generally several ways to achieve passive Q-switching such as semiconductor saturable absorber mirrors (SESAMs) [6], carbon nanotubes (CNTs) [7] and graphene [8] and so on. To obtain passively mode-locked fiber laser, except for the methods mentioned above, nonlinear polarization rotation (NPR) [9], NOLM [10] and nonlinear amplifier loop mirror (NALM) [11] are exploited over past decades, too.…”

2 µm actively Q-switched all fiber laser based on stress-induced birefringence and commercial Tm-doped silica fiber

“…Both the passive and active Q-switched fiber lasers have been investigated at 2 mm wavelength region. Passive Q-switched fiber lasers can be achieved by using the saturable absorbers (SAs), such as crystals doped with ions like Cr 2 þ , Cr 4 þ , V 3 þ , or Co 2 þ , semiconductor saturable absorber mirrors (SESAMs) and graphene [4][5][6]. As to the active Q-switching, it allows for more control over the characteristics of the output pulse.…”