Manipulation of operation states by polarization control in an erbium-doped fiber laser with a hybrid saturable absorber

Abstract

We propose an operation switchable ring-cavity erbium-doped fiber laser (EDFL) via intra-cavity polarization control. By using a semiconductor saturable absorber mirror in the EDFL cavity, stable Q-switching, Q-switched mode-locking, continuous-wave mode-locking, pulse splitting, and harmonic mode-locking pulses can be manipulated simply by detuning a polarization controller while keeping the pump power at the same level. All EDFL operation states can be obtained under the polarization angles detuning within 180 degrees. Continuous-wave mode-locking of EDFL with 800-fs pulsewidth repeated at 4 MHz has been obtained, for which the output pulse energy is 0.5 nJ and the peak power is 625 W. Interaction between solitons and the accompanied non-soliton component will lead to either pulse splitting or 5th-order harmonic mode-locking at repetition rate of 20 MHz.

Quasi mode-locking of coherent feedback random fiber laser

“…2f, wherein mode-locking pulses can be clearly observed within the Q-switched envelope. Unlike the typical Q-switched mode-locking pulse33, we observed mode-locking pulses in both the low frequency and the high frequency regimes. For example, low frequency pulses (see Fig.…”

Harmonic Order-Dependent Pulsewidth Shortening of a Passively Mode-Locked Fiber Laser With a Carbon Nanotube Saturable Absorber

“…Only the screw of the PC is accessible to adjust the HML order during the experiment. The intracavity polarization plays an important role to obtain stabilized HML [14]. A programmable controlled PC is inserted to record the polarization change for different HML orders quantitatively.…”

“…An ML/HML switchable EDFL, with its pulsewidth varying at different HML orders, was also demonstrated by different pumping powers. Either the ML or the HML can be initiated with a semiconductor saturable absorber mirror (SESAM) and adjusted by controlling the intracavity polarization [14].…”

Passively Q-switched tri-wavelength Yb^3+:GdAl_3(BO_3)_4 solid-state laser with topological insulator Bi_2Te_3 as saturable absorber

“…For decades, many successful Q-switched lasers have been realized by exploiting a variety of SAs such as transitionelement-doped (Cr 4 [7,8], V 3 [9,10], and Co 2 [11]) host materials and semiconductor saturable absorber mirrors (SESAMs) [12][13][14][15]. However, it should be noted that the applications of these traditional SAs are somehow limited due to their narrow absorption band and high cost.…”