Wideband multiwavelength Brillouin-Erbium fiber laser (BEFL) utilizing a linear cavity is presented, highlighting the usage of higher Brillouin and lower erbium doped-fiber pump powers to achieve higher lasing spectral bandwidth. A tuning range of 60 nm has been obtained from 1525 to 1585 nm. The dependency of the Stokes signal tuning range on the laser's pumping power is also elaborated. The wide tuning range of the proposed BEFL has potential in dense wavelength division multiplexing communication systems.

We investigate the amplitude flatness of Rayleigh-assisted Brillouin-Raman comb laser in a linear cavity in which feedbacks are formed by high-reflectivity mirror. The optimization of Brillouin pump power and wavelength is very crucial in order to obtain a uniform power level between Stokes lines. The Brillouin pump must have a relatively large power and its wavelength must be located closer to the Raman peak gain region. The flat-amplitude bandwidth is also determined by the choice of Raman pump wavelengths. A flat-amplitude bandwidth of 30.7 nm from 1527.32 to 1558.02 nm is measured when Raman pump wavelengths are set to 1435 and 1450 nm. 357 uniform Brillouin Stokes lines with 0.086 nm spacing are generated across the wavelength range. The average signal-to-noise ratio of 17 dB is obtained for all the Brillouin Stokes lines.

We demonstrate a multiwavelength Brillouin-erbium fiber laser with double-Brillouin-frequency spacing. The wider channel spacing is realized by circulating the odd-order Stokes signals in the Brillouin gain medium through a four-port circulator. The circulated odd-order Stokes signals are amplified by the Brillouin gain and thus produce even-order Stokes signals at the output. These signals are then amplified by erbium gain block to form a ring-cavity laser. Ten channels with 0.174 nm spacing that are generated at 0.5 mW Brillouin pump power and 150 mW pump power at 1480 nm can be tuned from 1556 nm to 1564 nm. The minimum optical signal-to-noise ratio of the generated output channels is 30 dB with maximum power fluctuations of ±0.5 dB.

We experimentally demonstrate a simple widely tunable multiwavelength Brillouin/Erbium fiber laser that can be tuned over the entire C-band, thereby greatly improving the tuning range limitation faced by the previous Brillouin-erbium fiber laser architectures. Tuning range of 39 nm from 1527 nm to 1566 nm, which is only limited by the amplification bandwidth of the erbium gain was successfully achieved. At Brillouin pump wavelength of 1550 nm and 1480 nm laser pump and Brillouin pump powers of 130 mW and 2 mW respectively, all the generated output channels have peak power above 0 dBm, with the first output channel having a peak power of 8.52 dBm. The experimental set up that consists of only 4 optical components, is simple, devoid of the complex structure employed previously to enhance the tunability and feedback mechanism normally associated with multiwavelength Brillouin-erbium fiber laser sources. The generated output channels are stable, rigidly separated by 10 GHz (0.08 nm).

Abstract:In this paper, a multiwavelength linear-cavity Brillouin-Erbium fiber laser pumped by a 1480 nm pump laser is demonstrated to operate in the L-band region. The issue of low gain efficiency of L-band in Erbium-doped fiber pumped with 980 nm pump lasers is resolved with this pumping scheme. The amount of 1480 nm pump power to produce the first Brillouin Stokes line oscillating in the cavity is 23.4 mW only. The proposed laser configuration has a wide tuning range of 16 nm from 1591 to 1607 nm with six Brillouin Stokes lines within this tuning range. The maximum number of 23 Brillouin Stokes lines with a spacing of 0.089 nm is achieved by setting the Brillouin pump wavelength at 1595.5 nm and its power is set at 3.2 mW. Wavelength, nmOutput spectrum of L-band linear cavity BEFL at BP power of 3.2 mW, BP wavelength of 1595.5 nm and 1480 nm pump power is set to 100 mW