Evanescent-Light Deposition of Graphene Onto Tapered Fibers for Passive Q-Switch and Mode-Locker

Abstract

We demonstrate the fabrication of graphene-deposited tapered fibers (GDTFs), which can be used as saturable absorbers (SAs) for pulsed lasers. The advantages of GDTF SAs include flexibility, all-fiber configuration, and high optical damage threshold. The fabrication process is based on the interaction of the evanescent field of a tapered fiber with graphene. By in situ monitoring the transmitted power, the deposition process can be controlled, and the GDTF with a desirable level of nonsaturable absorption loss can be fabricated. We also study the dynamic deposition process by employing different waist diameters of tapered fibers and the different deposition powers. The results show that the deposition time can be significantly shortened with stronger evanescent field by decreasing the taper diameter or increasing the deposition power. Furthermore, by exploiting the GDTF as an intracavity passive power modulating element, we demonstrate efficient Q-switched and mode-locked erbium-doped fiber lasers, respectively.National Natural Science Foundation of China [61107038, 61177044]; Natural Science Foundation of Fujian Province of China [2011J01370]; Fundamental Research Funds for the Central Universities of China [2010121059]; Science and Technology on Electronic Information Control Laborator

Highly Stable Passively Q-Switched Erbium-Doped All-Fiber Laser Based on Niobium Diselenide Saturable Absorber

“…By simulating the measured data with Equation (1), the modulation depth, saturation intensity, and nonsaturable loss are 16.2%, 0.76 MW/cm 2 , and 14%, respectively. Compared with the results reported in previous work [33,34], the NbSe2 SA has a higher modulation depth and a lower saturation intensity in this work. For the D-shaped fiber-based SA, its saturable absorption arises from the interaction between the evanescent field outside the D-shaped fiber and SA, introducing a large unsaturable loss due to the large interaction area.…”

Optical properties and applications of SnS₂ SAs with different thickness

“…The effect of SA with different nonlinearity on the performance of corresponding lasers is also obvious. The experimental results show that the output power based on SA with 40.5% modulation depth is the most stable (standard deviation: 0.493 mW), this is due to SA with high modulation depth can promote the stability of the system according to the previous research 33 . In addition, SA with large modulation depth seems to have a slight advantage in achieving short pulse.…”

Graphene-based optical modulators

“…optical communication system, was fabricated by Li et al [53]. The structure they used is a graphene-clad microfiber (GCM), as is shown in Figure 8a, which has been reported for mode-locked fiber lasers [54,55]. When 1,060-nm pump laser pulses (approximately 5 ns, 24 kHz) and 1,550-nm CW light were coupled to the GCM (Figure 8b, Module 2), it was found that the photodetector cannot follow due to the slow recovery time.…”