Widely tunable linear-cavity multiwavelength fiber laser with distributed Brillouin scattering.

We demonstrate a multiple wavelength Brillouin/erbium fiber laser in a linear cavity configuration. The laser cavity is made up of a fiber loop mirror on one end of the resonator and a virtual mirror generated from the distributed stimulated Brillouin scattering effect on the other end. Due to the weak reflectivity provided by the virtual mirror, self-lasing cavity modes are completely suppressed from the laser cavity. At Brillouin pump and 1480-nm pump powers of 2 and 130 mW, respectively, 11 channels of the demonstrated laser with an average total power of 7.13 dBm can freely be tuned over a span of 37-nm wavelength from 1530 to 1567 nm

All-optical wavelength conversion based on degenerate four-wave mixing in Raman ring laser.

We demonstrate an all-optical wavelength converter using a ring cavity that produces conversion efficiency of more than unity within a certain bandwidth. The highly nonlinear fiber is used as the parametric amplifying medium and it is pumped by four independent pump lasers at 1427, 1443, 1461, and 1493 nm. The parametric pump is formed internally from the ring cavity through the effect of stimulated Raman scattering. The interaction between signal and parametric pump becomes intensified as they propagate along the fiber from input to the output ports. This un-depleted pump power condition enhances the process of degenerate four-wave mixing in the proposed structure. The maximum conversion efficiency is obtained at 9.5 dB and the bandwidth of positive conversion efficiency is about 20.6 nm

Multiwavelength L-band fiber laser with bismuth-oxide EDF and photonic crystal fiber.

A multiwavelength laser comb using a bismuth-based erbium-doped fiber and 50 m photonic crystal fiber is demonstrated in a ring cavity configuration. The fiber laser is solely pumped by a single 1455 nm Raman pump laser to exploit its higher power delivery compared to that of a single-mode laser diode pump. At 264 mW Raman pump power and 1 mW Brillouin pump power, 38 output channels in the L-band have been realized with an optical signal-to-noise ratio above 15 dB and a Stokes line spacing of 0.08 nm. The laser exhibits a tuning range of 12 nm and produces stable Stokes lines across the tuning range between Brillouin pump wavelengths of 1603 nm and 1615 nm

OSNR enhancement utilizing large effective area fiber in a multiwavelength Brillouin-Raman fiber laser.

We propose a simple Brillouin-Raman multichannel fiber laser with supportive Rayleigh scattering in a linear cavity without employing any feedback mirrors at the end of cavity. Brillouin and the consequences of Rayleigh scattering work as virtual mirrors. We employ a section of large effective area fiber in addition to a section of dispersion compensating fiber to enhance the optical signal-to-noise ratio of multi-channel Brillouin-Raman comb fiber laser. We able to produce a flat comb fiber laser with 37 nm bandwidth from 1539 to 1576 nm built-in 460 Stokes lines with 0.08 nm spacing. Furthermore, this Brillouin-Raman comb fiber laser has acceptable optical signal-to-noise ratio value of 16.8 dB for the entire bandwidth with excellent flatness and low discrepancies in power levels of about 2.3 dB between odd and even channels

Optimisation of remotely-pumped EDFA location for unrepeatered transmission systems

In this paper, a new technique of determining the location of a remotely-pumped Erbium doped fibre amplifier (R-EDFA) in unrepeatered transmission system is presented. The location of the R-EDFA is varied over the transmission span with its optimised pump power. The unrepeatered transmission link is optimised when the R-EDFA is located closer to the receiver end

Efficient technique for intracavity loss optimization in a dual-wavelength erbium-doped fiber laser

An efficient technique to improve the quality of a tunable dual-wavelength fiber laser is reported. The power of both channels can be equalized with efficient intracavity loss optimization. The maximum power difference between the two wavelengths is less than +/- 0.37 dB and the output power is approximately flat within C-band

Improvement of comb lines quality employing double-pass architecture in Brillouin-Raman laser.

We demonstrate a generation of multiple wavelength lasers incorporating a Brillouin-Raman fiber laser using a double-pass structure. The Raman and Brillouin amplification medium is provided by the combination of 11 km long dispersion-compensating-fiber and 25 km long large-effectivearea-fiber. The laser structure is primarily pumped by single Raman pump wavelength at 1455 nm. The loop mirror is utilized as the reflector, which allows Stokes lines and pump light to propagate back into the cavity. A flat output of multiwavelength lasers with uniform optical signal-to-noise ratio across the flat bandwidth is realized from the proposed laser structure