Gain-flattened S-band depressed cladding erbium doped fiber amplifier with a flat bandwidth of 12 nm using a Tunable Mach-Zehnder Filter

S-band amplification is an important area of optical communications research, focusing on meeting the ever-increasing demands for traffic bandwidth as the C- and L-bands approaches to their limits. In this paper a novel method of providing an S-band optical amplifier with a flat gain-bandwidth is proposed. The proposed method utilizes a Depressed Cladding Erbium Doped Fibre together with a Tunable Mach-Zehnder Filter as to generate a flat amplification bandwidth of 12 nm stretching from 1492 to 1504 nm. The average gain value is approximately 24.21 dB, with a peak to peak fluctuation of 0.83 dB and a noise figure ranges from 7.13 to 10.94 dB for input signals of 1484 to 1510 nm.     

S-band multiwavelength Brillouin Raman Fiber Laser

In this paper we propose and demonstrate an S-band Brillouin-Raman Fiber Laser (BRFL). The S-band BRFL utilizes a Dispersion Compensating Fiber (DCF) as the non-linear gain medium in a linear cavity configuration and amplified by two 1425 nm, 380 mW pumped Raman Fiber Amplifiers (RFAs). A Brillouin Pump (BP) signal of 1515 nm at 12 dBm in power is injected into the setup to generate Stokes lines via the Stimulated Brillouin Scattering (SBS) process. The S-band BRFL is able of generating a Brillouin comb with 32 Stokes lines with a flat peak output power of − 18 dBm. The best BP to Stokes power ratio of the system is determined to be 50:50, while a ratio of 70:30 is observed to generate Stokes with a higher peak power, but at the expense of the number of wavelengths. The S-band BRFL has many potential applications as multiwavelength sources for communications and sensors.     

Stable zirconia-erbium doped multiwavelength fiber laser by precise control of polarization states

A compact zirconium-erbium doped fiber (Zr-EDF) based multiwavelength fiber laser (MWFL) with stable output comb is proposed and demonstrated. The MWFL utilizes a 3 m long Zr-EDF with an erbium concentration of 3000 ppm and pumped by a 1480 nm laser diode (LD) as the active gain medium. A fiber based multimode polarization controller (PC) is used to precisely control the polarization states of the oscillating modes in the MWFL, distributing the total energy of the system among the lasing wavelengths in order to overcome the mode-suppression and mode-competition that arises from homogenous line broadening. The MWFL is capable of generating up to four lasing wavelengths with average peak powers of 0.08 dBm in the extended L-band of 1600 nm. The lasing wavelengths have a 3-dB linewidth of 0.1 and an extinction ratio of 40 dB as well as highly stable, with minimal fluctuations of less than 0.6 dB observed in the peak powers of the lasing wavelengths over a period of 1 h. The proposed system allows for the realization of a compact, cost-effective and stable erbium based MWFL capable of operating at room temperature.