M.H.A. Wahid

Correlation of Brillouin Stokes Signals and Optical-Signal-to-Noise-Ratio in Multi-Wavelength Brillouin Fiber Laser with Additional Fiber Bragg Grating

We experimentally demonstrate unidirectional propagation of multi-wavelength Brillouin fiber laser system with additional fiber Bragg grating. The configuration is arranged in a ring resonator by utilizing five different Brillouin gain mediums. In this experiment, the input Brillouin pump power was varied in order to maximize the generated Brillouin Stokes signals based on the respective fiber lengths. The influence of these controllable parameters leads to the correlation between of Brillouin Stokes signals and optical-signal-to-noise-ratio. In this case, at 10 km of single mode fiber the maximum of 38 Brillouin Stokes signals were generated together with 15.07 dB of average optical-signal-to-noise-ratio when the 17 dBm Brillouin pump power was launched into the ring resonator.

Lasing characteristics of 10 GHz signal spacing in a ring cavity multi-wavelength Brillouin fiber laser employing fiber Bragg grating

This paper experimentally demonstrated a ring cavity multi-wavelength Brillouin fiber laser employing fiber Bragg grating (FBG) that operated in the C-band region. The FBG plays a significant role to reflect signals and filter selected wavelengths. A number of generated Brillouin Stokes (BS) signals and tuning range ability were investigated. A 9km length of single mode fiber was utilized to provide a Brillouin gain medium for generating stimulated Brillouin scattering effect. In this work, at optimum output coupling ratio of 90% and Brillouin pump (BP) wavelength of 1550nm, up to a maximum of 26 BS signals were recorded by injecting 63.1mW of amplified BP powers. The BS signals were also tunable within the ranges of 1544–1556nm in accordance with the FBG properties at 3dBm bandwidth of 5nm.

All-Optical XOR Logic Gates: Insights and Comparisons

Three XOR photonics logic gate configurations namely semiconductor optical amplifier-Mach Zender interferometer cross phase modulation (SOA-MZI XPM), SOA-MZI cross gain modulation (XGM) and terahertz optical asymmetrical demultiplexer (TOAD) XOR are analysed and compared in terms of generated power, optical signal-to-noise ratio (OSNR) values and bit error rate (BER) signal quality. The highest generated power is possessed by the TOAD at 23.5 dBm, the SOA-MZI XPM showed the most extinction ratio or OSNR with 109.6 dB whereas the best BER is recorded in the SOA-MZI XGM at 4.42 x 10-22.

Fiber Length Optimization of Ring Cavity Multi-Wavelength Brillouin Fiber Laser Utilizing Fiber Bragg Grating

In this paper, we experimentally investigated the performance of ring cavity multi-wavelength Brillouin fiber laser utilizing fiber Bragg grating which operated in the C-band wavelength region. The combination of stimulated Brillouin scattering and selective wavelengths gave a new invention in the optical fiber communication. Five different lengths of single mode fiber are used in order to get the best gain medium for stimulated Brillouin scattering effect. Up to 33 of Brillouin Stokes signals and 31 of anti-Stokes signals were obtained when 10 km fiber length was used in the laser system. The average value optical signal to noise ratio of 15 dB has been achieved. The broadening bandwidth of Brillouin Stokes signals also occurred at the center wavelength of 1550 nm based on the 3 dB bandwidth of 5 nm fiber Bragg grating.

Optimization of Output Coupling Ratio for Multi-Wavelength Brillouin Fiber Laser Employing FBG and DCF as Gain Medium

A ring-cavity multi-wavelength Brillouin fiber laser by employing a fiber Bragg grating and dispersion compensating fiber was experimentally demonstrated. The multi-wavelength Brillouin fiber laser has been analyzed at different output coupling ratios at 1550 nm of Brillouin pump wavelength. A ring-cavity multi-wavelength Brillouin fiber laser has been designed with a 16 km long of dispersion compensating fiber which acts as gain medium for stimulated Brillouin scattering effect. Dispersion compensating fiber is designed to have small core size and has higher nonlinear coefficient. As a result, 8 Brillouin Stokes signals were produced at maximum Brillouin power of 21 dBm and output coupling ratio of 80%. The best performance of output coupling ratio was determined by 70% with the highest of signal to noise ratio at 38.39 dB.

High Speed All-Photonic Flip-Flop Operation at a Single Wavelength

This work is based on dual Mach-Zehnder interferometer with semiconductor optical amplifiers in both arms. The proposed flip-flop operates at a single wavelength. A bidirectional coupler is placed at the end of the system to observe the output at set and reset terminals. The signals modulate the injected photon rate in the SOAs thus forming photonic flip-flop function. The photon injection rate is modulated due to self-gain modulation and self-phase modulation that occur in the SOAs towards demonstrating optical bistability. Switching between states of the flip-flop occur at full width half maximum of 32 ps. The output power of this flip-flop is around 24.5 mW. It is observed that the switching energy can be adjusted to a low level by decreasing the injected currents into the SOAs. The injection and the input power are the two parameters that govern the whole operation of the designed flip-flop.

Comparative Characteristics between L-Band EDFA, L-Band EDFA Utilising Single FBG and Dual Stage L-Band EDFA Utilising Dual FBG Configurations

The development was conducted with three configurations of L-Band EDFA, L-Band EDFA utilising Single FBG and Dual Stage L-Band EDFA utilising Dual FBG. The configurations utilising the FBG using 35 meter M-12 Fibercore EDF as the gain medium to amplify the input signal power in the L-band region. The gain enhancement has shown by the Dual Stage L-Band EDFA utilising Dual FBG by injecting low input signal power of -10 dBm. The flat amplitude of OSNR at 33.358 dB was produced at injected wavelength from 1570 nm to 1605 nm.

S-shaped S-band multi-wavelength Brillouin Raman Fiber Laser employing Raman amplifier

The simulation demonstrated an S-shaped multi-wavelength Brillouin-Raman Fiber Laser employing Raman amplifier in the cavity. Raman amplifier- average power model is employed for signals amplification. This configuration is operated in the S-band wavelength region with tuning range between 1460 nm to 1530 nm. A laser signal at 1500 nm with 4 dBm of output power act as the Brillouin pump, while at output power of 90 mW with 1425 nm of wavelength act as the Raman pump. As a result, at 10 km of single mode fiber and output coupling ratio of 90%, 7 outputs of Brillouin Stokes signals are obtained with maximum output power of 33.88 dBm. Meanwhile, maximum gain values at 38. 07 dBm is recorded at 90 mW of injected Raman pump power. It is notable that the Raman gain broadening occurs around 1500 nm to 1530 nm in S-band wavelength region.

L-band single-wavelength Brillouin fiber laser utilizing ring cavity

In this paper we demonstrate a single-wavelength Brillouin Fiber laser utilizing ring cavity which operated in the L-band wavelength region. The Brillouin gain medium is provided by 4 km long of Single Mode Fiber. Based on the experimental result, it shows that the maximum output Brillouin power of 9.73 dBm with an average value of 8.5 dBm was obtained as the Brillouin pump power of 16.0 dBm and pump wavelength of 1580 nm were applied to the system. The output Brillouin Stokes power was directly dependence on the value of output Brillouin power. The optical-to-noise ratio of 43.1 dB has been generated from the system. Furthermore, without any self-lasing cavity modes activities, single-wavelength BFL is able to operate freely across L-band wavelength region.

Double spacing multi-wavelength Brillouin Raman fiber laser of eight-shaped structure utilizing Raman amplifier

In this paper, double frequency spacing of multi-wavelength Brillouin Raman fiber laser utilizing eight-shaped structure in conjunction with Raman amplifier is simulated and demonstrated using Optisys software. Double frequency multiwavelength Brillouin Raman fiber laser is one of the solution for single frequency spacing channel de-multiplexing from narrow single spacing in the communication systems. The eight-shaped structure has the ability to produce lower noise and double frequency spacing. The 7 km of single mode fiber acting as a nonlinear medium for the generation of Stimulated Brillouin Scattering and Stimulated Raman Scattering. As a results, the optimum results are recorded at 1450 nm of RP power at 22 dBm and 1550 nm of BP power at 20 dBm. These parameters provide a high output peak power, gain and average OSNR. The highest peak power of Stokes 1 is recorded at 90% of coupling ratio which is 29.88 dBm. It is found that the maximum gain and average OSNR of about 1.23 dB and 63.74 dB.