We demonstrate a Q-switched Raman fiber laser using molybdenum disulfide (MoS2) as a saturable absorber (SA). The SA is assembled by depositing a mechanically exfoliated MoS2 onto a fiber ferrule facet before it is matched with another clean ferrule via a connector. It is inserted in a Raman fiber laser cavity with a total cavity length of about 8 km to generate a Q-switching pulse train operating at 1560.2 nm. A 7.7-km-long dispersion compensating fiber with 584 ps•nm −1 km −1 of dispersion is used as a nonlinear gain medium. As the pump power is increased from 395 mW to 422 mW, the repetition rate of the Q-switching pulses can be increased from 132.7 to 137.4 kHz while the pulse width is concurrently decreased from 3.35 𝜇s to 3.03 𝜇s. The maximum pulse energy of 54.3 nJ is obtained at the maximum pump power of 422 mW. These results show that the mechanically exfoliated MoS2 SA has a great potential to be used for pulse generation in Raman fiber laser systems.

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Abstract. We demonstrate the generation of continues-wave (CW) laser based on BrillouinRaman fiber laser (BRFL) by incorporating a 7.7 km long dispersion compensating fiber (DCF) as a nonlinear gain medium. The 1455 nm Raman pump (RP) was launched into the DCF via a wavelength division multiplexing (WDM). At 645 mW pump power, stable CW laser presence at 1563.5 nm (1 st stokes), 1563.4 (2 nd stokes) nm and 1563.3 nm (3 rd stokes). Those peak wavelengths have produced most identical output power. This finding proves our ring laser cavity has the capability to generate stable CW BRFL. Thus, it potentially to generate pulse laser operation in the future work.

An efficient and compact double-pass optical fiber amplifier is demonstrated using a newly developed hafnia bismuth erbium co-doped fiber (HBEDF) as a gain medium. The HBEDF is fabricated using a modified chemical vapor deposition in conjunction with solution doping. The fiber has an erbium ion concentration of 12500 ppm. At the optimum length of 0.5 m, the HBEDF amplifier (HBEDFA) achieves a flat gain of 26 dB with a gain variation of less than 1.5 dB within a wavelength region from 1530 to 1560 nm when the input signal and pump power are fixed at −30 dBm and 140 mW, respectively. On the other hand, at the input signal power of −10 dBm, the HBEDFA also achieves a flat gain of 14.2 dB with a gain variation of less than 2.5 dB within a wide wavelength region from 1525 to 1570 nm. Compared with the conventional zirconia erbium co-doped fiber based amplifier, the proposed HBEDFA obtains a more efficient gain and lower noise figure. For an input signal of −30 dBm, the gain improvements of 6.2 dB and 4.8 dB are obtained at 1525 nm and 1540 nm, respectively.

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