Graphene-based passively Q-switched dual-wavelength erbium-doped fiber laser

Abstract

We demonstrate a compact Q-switched dual-wavelength erbium-doped fiber (EDF) laser based on graphene as a saturable absorber (SA). By optically driven deposition of graphene on a fiber core, the SA is constructed and inserted into a diode-pumped EDF laser cavity. Also benefiting from the strong third-order optical nonlinearity of graphene to suppress the mode competition of EDF, a stable dual-wavelength Q-switching operation has been achieved using a two-reflection peak fiber Bragg grating as the external cavity mirror. The Q-switched EDF laser has a low pump threshold of 6.5 mW at 974 nm and a wide range of pulse-repetition rate from 3.3 to 65.9 kHz. The pulse duration and the pulse energy have been characterized. This is, to the best of our knowledge, the first demonstration of a graphene-based Q-switched laser.

Dual-wavelength passively Q-switched Erbium-doped fiber laser with MWCNTs slurry as saturable absorber

“…The generated pulse produced maximum pulse energy and maximum peak power of 11.97nJ and 2.05mW, respectively at maximum input pump power. The recorded signal to noise ratio is about 62dB and shows that the proposed MWCNTs slurry based SA is able to generate dual wavelength Qswitched pulse laser with a high stability pulse.The generation of high energy laser pulses often utilizes Q-switching fiber lasers technology that brings about various applications in many industrial and scientific sectors including laser processing, medicine, telecommunications, range finding, metal cutting and remote sensing [1][2]. Actively Q-switched fiber lasers use optical modulation devices which made them more complicated as compared to the passively Q-switching techniques.…”

“…The generation of high energy laser pulses often utilizes Q-switching fiber lasers technology that brings about various applications in many industrial and scientific sectors including laser processing, medicine, telecommunications, range finding, metal cutting and remote sensing [1][2]. Actively Q-switched fiber lasers use optical modulation devices which made them more complicated as compared to the passively Q-switching techniques.…”

“…In a fiber laser, the generation of a passively dual wavelength laser was demonstrated by using a various range of materials as a saturable absorber, including selenium bismuth (Bi 2 Se 3 ), graphene, tungsten disulphide (WS 2 ), molybdenum disulphide (MoS 2 ), black phosphorus (BP) as well as SWNTs, among many others [1][2][3][4][11][12][13][14]. For instance, passively Q-switched EDFL based on a SWNT/polymide polymer composite based saturable absorber was shown to oscillate simultaneously at 1532nm and 1558nm with 26nm peak separation within the range input pump power from 62mW to 120mW [1].…”

“…Though it is thought that the said SA is ideal with an all-fiber cavity configuration, many researches have been continuously conducted to find a better if not the best SA to surmount the drawbacks of the previous SAs. SESAMs fabrication is complex, intricate and expensive [2][3]. It also has a narrow operation waveband and limited range of optical responses.…”

“…For instance, passively Q-switched EDFL based on a SWNT/polymide polymer composite based saturable absorber was shown to oscillate simultaneously at 1532nm and 1558nm with 26nm peak separation within the range input pump power from 62mW to 120mW [1]. Graphene-based SA is also widely used in Q-switched dual wavelength pulse laser generation taking examples of the work by Luo et al [2] and Wang et al [13] [4]. MWCNTsbased SA is often used in obtaining a multi-wavelengths spectrum, one of which is reported by Tiu et al which produces at least 14 lines with a spectral range of 0.48nm using MWCNTs-PVA composite [15].…”