Brillouin-erbium Fiber Laser Research Articles

Widely tunable multiwavelength Brillouin-erbium fiber laser by eliminating self-lasing cavity modes

A linear multiwavelength Brillouin/erbium fiber laser (MWBEFL) with 40 nm tuning range is presented.The characteristic of opposite transmission of Brillouin Stokes (BS) signals in stimulated Brillouin scattering is used as reflector in one end of the fiber laser. The influence of the self-lasing modes existing in conventional MWBEFLs is eliminated, because there is no physical mirror at one end of the linear cavity. The threshold power is reduced, and the generation of BS signals is enhanced owing to the double-pass preamplification for the Brillouin pump by the erbium-doped fiber amplifier before entering the single-mode fiber. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:612–614, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26604

Realization of a low threshold multiwavelength brillouin/erbium f iber laser by optimizing the reflected power

A multiwavelength Brillouin/erbium fiber laser (BEFL) with low threshold power is realized. A low threshold power of 3 mW and a wide tuning range of 18 nm can be achieved by controlling the reflected power in the nonlinear optical loop mirror (NOLM). Up to 24 lines with a wavelength spacing of 0.086 nm are generated at the Brillouin pump and at the 1 480-nm pump with ?0.5 dBm (0.9 mW) and 25 mW of power, respectively.

Broadly tunable L-band multiwavelength BEFL utilizing nonlinear amplified loop mirror filter

We demonstrate a widely tunable L-band multiwavelength Brillouin-erbium fiber laser utilizing a nonlinear amplified fiber loop mirror filter (AFLMF). By manipulating polarization controllers placed in the fiber loop, the erbium peak gain spectrum is able to be shifted. The nonlinear AFLMF induces wavelength-dependent cavity loss and serves as an amplitude equalizer. In addition, it provides flexibility on controlling the amount of light reflected and transmitted into and out of the laser's cavity. By utilizing 100 mW 1480 nm pump and 1.1 mW Brillouin pump power, an average of 24 stable output channels are generated by the proposed structure that could all be tuned over the whole L-band window from 1570 nm to 1610 nm.

An Efficient Photonic Crystal Fiber-Based Brillouin Erbium Fiber Laser Using a Fiber Bragg Grating for Multi-Wavelength Generation

An efficient multi-wavelength Brillouin erbium fiber laser is demonstrated using an improved configuration with a broadband fiber Bragg grating and a piece of photonic crystal fiber. The laser generates more than 55 lines of optical comb with a line spacing of approximately 0.09 nm in a 1,565-5 nm region using pump powers of 3 dBm and 150 mW for the Brillouin and 980-nm pumps, respectively. The Brillouin erbium fiber laser with a fiber Bragg grating's reflectivity of 50% obtained a higher number of comb lines compared to that of 99% reflectivity.

Optical generation of microwave/millimeter‐wave based on Brillouin‐Erbium fiber laser

AbstractA novel system configuration for optical generation of microwave/millimeter‐wave (mm‐wave), which is realized through Brillouin‐Erbium fiber laser (BEFL), is investigated.The microwave/mm‐wave is generated by the mixing of the nth‐order Stokes wave and the pump wave on the high‐speed photodetector. The nth‐order Stokes wave is generated in the BEFL and filtered out by fiber Bragg grating. The experiments are carried out based on such configuration, and experimental results verify the validity of it. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26118

Multiwavelength Brillouin-erbium fiber laser with double-Brillouin-frequency spacing

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.

GENERATION OF NANOSECOND OPTICAL PULSES WITH CONTROLLED REPETITION RATE USING IN-CAVITY INTENSITY MODULATED BRILLOUIN ERBIUM FIBER LASER

A multimode Brillouin Erbium Fiber Laser BEFL, at 1550nm band, with in-cavity intensity modulation is demonstrated. The output of the laser is in the form of nanosecond pulses. The longitudinal mode separation is increased, which results in both reducing the number of oscillation modes and, at the same time, changing the output pulses repetition rate to be multiples of the round trip cavity frequency. It is also demonstrated that the number of modes is greatly reduced by the combination of active mode locking and the group velocity dispersion arising from the change in the refractive index at each mode due to the change in its gain within the Brillouin gain bandwidth. A case of a quasi single mode is reached where the output is nearly CW with very low sinusoidal modulation index.

Investigation on stimulated Brillouin scattering characteristics in a highly doped Bismuth-based Erbium-doped fiber

Stimulated Brillouin scattering (SBS) characteristics in a 49 cm long highly doped Bismuth-based Erbium doped fiber (Bi-EDF) is investigated in the ring and linear cavity configurations. At Brillouin pump (BP) power of 6 dBm, the Brillouin laser peak power of the optimized ring Brillouin Erbium fiber laser (BEFL) is obtained at 23 dB higher than the peak power of the conventional linear cavity at an up shifted wavelength of 0.08 nm. This Bi-EDF ring cavity operates at nearly 1563 nm wavelength region, which is up-shifted by 0.08 nm from the Brillouin pump wavelength with the side mode suppression ratios (SMSR) of 29 and 23 dB in the forward and backward directions, respectively.

A novel-configuration multi-wavelength Brillouin erbium fiber laser and its application in switchable high-frequency microwave generation

A novel configuration of compound-cavity multi-wavelength Brillouin erbium fiber laser is proposed and experimentally demonstrated. With an incident optical carrier power of 8 dBm, at least 14 lasing lines are obtained with a wavelength spacing of ∼0.08 nm. Stability and power uniformity of the multi-wave-length lasing are ensured by the flat hybrid gain of Brillouin and erbium, the compound-cavity structure, and the four-wave mixing suppression using a long (10 km) single-mode fiber. A stable and frequency-switchable microwave can be achieved by incorporating a fiber Bragg grating filter to select the desired nth-order Stokes wave and beating it with the optical carrier at a photodetector. In our experiment, the 1st-4th-order Stokes waves are filtered respectively and hence a high-quality microwave with a switchable frequency from ∼10 to ∼40 GHz and a tuning step of ∼10 GHz is achieved. The signal-to-noise ratio is measured to be >25 dB.

NUMERICAL MODELING OF EDFL AND BRILLOUIN ERBIUM FIBER LASER

Rigorous numerical models for the analysis of continuous wave operation of the erbium-doped fiber laser (EDFL) and Brillouin erbium fiber laser (BEFL) are demonstrated. The modeling of EDFL and BEFL (incorporating a non-linear gain medium), allows the behaviour of laser modes in their initial transient periods of operation to be analyzed. The analysis on competing modes in the laser cavity in determining the lasing wavelength, output power and spectral characteristics are not readily investigated via experimental approach. The results of the laser models in a steady state condition match acceptably well with the experimental data.

Multiple Brillouin Stokes generation with bismuth‐based erbium‐doped fiber

AbstractA multiple Brillouin Stokes generation is demonstrated at extended L‐band region using the bismuth‐based erbium‐doped fiber (Bi‐EDF) in the linear cavity. A 2.15‐m long Bi‐EDF is used to provide both nonlinear and linear gains to generate a stimulated Brillouin scattering (SBS) and to amplify the generated SBS, respectively. The Brillouin erbium fiber laser operates at 1615 nm region with more than 40 Stokes and anti‐Stokes lines, and the line spacing is measured to be ∼0.09 nm. Based on the four‐wave mixing signals spacing, the dispersion coefficient of the Bi‐EDF is estimated to be ∼95 ps/nm/km. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1416–1418, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25207

Compact Bi-EDF-Based Brillouin Erbium Fiber Laser Operating at the 1560-nm Region

A single-frequency Brillouin erbium fiber laser (BEFL) is demonstrated operating at the 1560-nm region using a simple ring resonator with a very short piece of bismuth-based erbium-doped fiber (Bi-EDF) for the first time. A 49-cm-long Bi-EDF is used to provide both nonlinear gain and linear gain to generate a stimulated Brillouin scattering (SBS) and to amplify the generated SBS, respectively. The BEFL operates at 1559.49 nm with a peak power of -4 dBm and a side-mode suppression ratio of 14 dB when the Brillouin pump (BP) and 1480-nm pump powers are fixed at 6 dBm and 144 mW, respectively. The BP wavelength is also tunable within a wavelength range from 1558.8 to 1560.0 nm.

Multiwavelength L-Band Brillouin–Erbium Comb Fiber Laser Utilizing Nonlinear Amplifying Loop Mirror

In this paper, we demonstrate a novel multiwavelength L-band Brillouin-erbium fiber laser utilizing nonlinear amplifying loop mirror. The erbium-doped fiber section in the fiber loop mirror provides efficient amplification of Brillouin pump (BP) to generate the stimulated Brillouin scattering in the single-mode fiber coil. The laser structure can achieve symmetry breaking of the loop without requirements to an asymmetric coupler or polarization controller. The proposed fiber laser has a low threshold power of about 10 mW to create the first Brillouin-Stokes signal. The maximum number of 27 Stokes signals with a spacing of 0.089 nm is achieved by setting the BP wavelength at 1604 nm and its BP power is set at 2.2 mW.

17-channels S band multiwavelength Brillouin/Erbium Fiber Laser co-pump with Raman source

In this paper, we propose and demonstrate a stable Brillouin-Erbium Fibre Laser (BEFL) capable of generating up to 17 lasing wavelengths in the Short-Wave length (S-band) region. The proposed setup uses a 7.7 km Dispersion Compensating Fibre (DCF) to act as a non-linear gain medium and a 30 m long Depressed-Cladding Erbium Doped Fibre (DC-EDF) as an optical amplifier for amplification in the S-band region. The proposed BEFL has an optimum tuning range of 1499 to 1502 nm and is capable of generating 17 lasing wavelengths with peak powers of between −20 to −15 dBm when injected with a Brillouin Pump (BP) of 5 dBm at 1499 nm and a Raman Pump (RP) of 300 mW at 1420 nm.

Tunable multiwavelength Brillouin–Erbium fiber laser by controlling self-lasing cavity modes’ oscillation

A novel and simple tunable multiwavelength Brillouin–Erbium fiber laser (BEFL) by controlling self-lasing cavity modes’ oscillation is demonstrated. With a variable optical attenuator (VOA) effectively optimizing the shape of the gain spectrum of the BEFL, the self-lasing cavity modes’ oscillation can be tuned in a large wavelength range, which can be used to enlarge the tunable multiwavelength range of the BEFL. A passive Erbium-doped fiber (EDF) gain section inserted in the BEFL cavity can help to further enlarge the tunable multiwavelength range of the BEFL and effectively suppress the cavity modes’ competition. With an EDF pump power of 50 mW and a Brillouin pump power of 1.2 mW, a tunable cavity modes’ oscillation range of 19.4 nm and a tunable multiwavelength range of 23 nm are obtained.

Optimization of Brillouin pump wavelength location on tunable multiwavelength BEFL

Optimization of Brillouin pump (BP) wavelength location on tunable multiwavelength Brillouin-erbium fiber laser (BEFL) with BP pre-amplified technique is experimentally investigated. The tunable multiwavelength BEFL is achieved by utilization a tunable band-pass filter in a laser cavity. The optimum BP power and BP wavelength location within the filter bandwidth is determined in order to obtain the maximum stable output channels. Optimum distance of launching the BP wavelength is found at 0.80 nm shorter from the center wavelength of the filter bandwidth. 15 stable output channels are achieved from the tunable fiber laser system within the optimum range of BP power which is found to be between 5.2 to 5.7 dBm.

Optimization of output coupling ratio on the performance of a ring-cavity Brillouin-erbium fiber laser

The operation of a single-wavelength Brillouin-erbium fiber laser (BEFL) system with a Brillouin pump preamplified technique for different output coupling ratios in a ring cavity is experimentally demonstrated. The characteristics of Brillouin Stokes power and tunability were investigated in this research. The efficiency of the BEFL operation was obtained at an optimum output coupling ratio of 95%. By fixing the Brillouin pump wavelength at 1550 nm while its power was set at 1.6 mW and the 1480 pump power was set to its maximum value of 135 mW, the Brillioun Stokes power was found to be 28.7 mW. The Stokes signal can be tuned within a range of 60 nm from 1520 to 1580 nm without appearances of the self-lasing cavity modes in the laser system.

On the pre-amplified linear cavity multi-wavelength Brillioun-erbium fiber laser with low SBS threshold highly nonlinear photonic crystal fiber

An efficient multi-wavelength Brillouin-erbium fiber laser utilizing low stimulated Brillouin scattering threshold highly nonlinear photonic crystal fiber (PCF) is presented. A Fabry-Perot pre-amplified Brillouin pump configuration was used which consists of 100 m PCF and 10 m erbium doped fiber (EDF). Up to 28 output channels with SNR of more than 20 dB could be generated with modest pump power.

Ring cavity multiwavelength Brillouin-erbium fiber laser with a partially reflective fiber Bragg grating

Utilization of a partially reflective fiber Bragg grating in the development of a multiwavelength Brillouin-erbium fiber laser is proposed. A ring cavity with a preamplified Brillouin pump configuration is implemented to demonstrate much better performance in comparison with the previously reported results obtained with different configurations. The combination of a 7 km long single-mode fiber and a 10 m long erbium-doped fiber ultimately yields the generation of up to twenty-one Brillouin Stokes lines. The laser configuration provides a greater tuning range of 21 nm at a Brillouin pump power of 2 mW and 980 nm pump power of 20 mW, and requires a much lower pump power to initiate lasing.

Directivity influence of signals propagation through EDFA gain medium of Brillouin–erbium fiber laser

We experimentally demonstrate a multiwavelength Brillouin–erbium fiber laser in two configurations; uni-directional and bi-directional propagation of Brillouin pump and Brillouin Stokes signals through an Erbium-doped fiber gain. The influence of these configurations on the performance of the output parameters in terms of lasing threshold, output channel generation and tuning range of the generated output channels are investigated. We discovered that there is a trade-off between these two fiber laser configurations. The uni-directional amplifier configuration provides greater tuning range of 46.8 nm against 23 nm at maximum Brillouin pump power of 2 mW and 1480-nm pump power of 130 mW. On the other hand, the bi-directional amplifier configuration provides 13 output channels against 6 output channels obtained from the uni-directional amplifier configuration at the same pumping powers. Nevertheless, the bi-directional amplifier configuration requires much lower pump power to initiate lasing.