N.A. Hassan

S-band multiwavelength ring Brillouin/Raman fiber laser with 20 GHz channel spacing.

We propose and demonstrate a tunable S-band multiwavelength Brillouin/Raman fiber laser (MBRFL) with a tuning range of between 1490 to 1530 nm. The proposed MBRFL is designed around a 7.7 km long dispersion compensating fiber in a simple ring configuration, acting as a nonlinear medium for the generation of multiple wavelengths from stimulated Brillouin scattering (SBS) and also as a nonlinear gain medium for stimulated Raman scattering (SRS) amplification. A laser source with a maximum power of 12 dBm acts as the Brillouin pump (BP), while two 1420 nm laser diodes with a total power of 26 dBm act as the Raman pumps (RPs). The MBRFL can generate a multiwavelength comb consisting of even and odd Stokes at an average power of -12 dBm and -14 dBm respectively, and by separating the even and odd Stokes outputs, a 20 GHz channel spacing is obtained between two consecutive wavelengths. Due to the four-wave mixing (FWM) effect, anti-Stokes lines are also observed. The multiwavelength comb generated is not dependent on the BP, thus providing high stability and repeatability and making it a highly potential source for many real-world applications. This is the first time, to the knowledge of the authors, that a tunable MBRFL has been developed using SRS to obtain gain in the S-band region.

Generation of mode-locked erbium-doped fiber laser using MoSe2as saturable absorber

Abstract. Mode-locked generation of erbium-doped fiber laser (EDFL) with MoSe2 thin film as saturable absorber is practically demonstrated. Bulk MoSe2 is exfoliated into few-layer MoSe2, which is achieved based on the liquid phase exfoliation technique. The few-layer MoSe2 is mixed with polyvinyl alcohol to become a thin film. Mode-locked occurs between pump powers of 65 and 218 mW. The mode-locked is operated at fundamental frequency of 8.8 MHz, and the spectrum is centered at 1560 nm. The SNR of mode-locked EDFL is more than 50 dB. At pump power of 218 mW, 91.3 pJ of pulse energy is achieved.

Single and Double Brillouin Frequency Spacing Multi-Wavelength Brillouin Erbium Fiber Laser With Micro-Air Gap Cavity

Single and double Brillouin frequency spacing multi-wavelength Brillouin Erbium-doped fiber laser based on micro-air gap cavity is proposed and demonstrated. A 6.90-km dispersion shifted fiber is used as Brillouin gain medium to induce stimulated Brillouin scattering in the ring cavity. The micro-air gap cavity is constructed by aligning two polished fiber facets coaxially, and induces strong Fresnel reflection to switch the Brillouin frequency spacing from a double spacing to single spacing regime. Under the Brillouin pump power of 13 dBm and the laser diode pump power of 300 mW, five Stokes with a wavelength spacing of 0.160 nm and six Stokes with a wavelength spacing of 0.084 nm are generated. The fluctuation of the Stokes for both single and double Brillouin spacing regimes in the proposed setup are less than 3 dB throughout a 1-h time span. The variation of the cavity efficiency between the single and double spacing regimes is less than 1.2 dB.

High gain S-band semiconductors optical amplifier with double-pass configuration

In this paper we propose and demonstrate a double-pass configuration of a compact high gain short wavelength (S-) band amplifier based on a semiconductor optical amplifier (SOA) operating from 1480 to 1520 nm. The proposed system provides gain value of 31.07 dB at a signal power level of −40 dBm taken at 1500 nm. The measure gain profile of the double-pass configuration over different power levels and at different signal wavelengths outperforms that of the single-pass configuration. The noise figure of both configurations averages out to 10 dB. This system provides a good alternative as a high-gain and compact amplifier in the S-band region.

Enhancement of Brillouin Stokes generation in the S-band region using a combination S-band Depressed Cladding Erbium Doped Fiber and Semiconductor Optical Amplifier

A hybrid Depressed-Cladding Erbium Doped Fiber (DC-EDF) together with a broadband Semi-conductor Optical Amplifier (SOA) to enhance the generation of Stokes and anti-Stokes in a 7.7 km long Dispersion Compensating Fiber (DCF) is proposed and demonstrated. The performance of the proposed system is compared against that of a conventional system with only the DC-EDF as the gain medium, and the incorporation of the SOA can be seen to enhance the generation of Brillouin Stokes significantly. The proposed system is able to generate an output comb with a flat-top and more than 29 Stokes and 13 anti-Stokes lines, an increase of 14 and 8 lines respectively over the conventional system and covering the entire S-band region. The output comb generated is highly stable over time.