Rayleigh assisted Brillouin effects in distributed Raman amplifiers under saturated conditions at 40 Gb/s

Abstract

mm. The strips of the three-line-microstrip section have a width of 1.4 mm and are separated a distance of 0.2 mm. The microstrip sections have a width of 4.6 mm to achieve a characteristic impedance of 50 X.For the circuit simulation, the characteristic impedances and propagation constants of the ee, oo, and oe modes have been obtained from an electromagnetic analysis performed with Agilent TM Momentum. The via holes have been modeled using the model proposed in [8]. Figure 5 compares the measured and simulated [using the circuit model of Figure 4(b)] S 11 and S 21 parameters of the designed filter, showing a good agreement. The measured and simulated insertions losses are 1.2 and 0.7 dB, respectively. The measured and simulated bandwidths are 9.7 and 10.1%, respectively. The results validate both the multimodal approach and the filter structure proposed in this letter. CONCLUSIONSIn this letter, a new two-pole compact BPF using an asymmetric short-circuited spurline resonator is presented. It has been analyzed by means of a new multimodal model for a microstrip to three-linemicrostrip cross. This multimodal model provides a useful tool to parametrically study the dependence of the filter performance on its dimensions. Based on this parametric study, a series of design rules has been obtained, which allow a rapid fine tuning of the filter central frequency and bandwidth. Finally, a BPF with a 1.9-GHz center frequency has been designed, simulated, and measured. Simulations and measurements show a good agreement, and therefore, validate both the filter structure and its multimodal model. ACKNOWLEDGMENTS

Brillouin effect characterization in all‐Raman amplified 4 × 40 Gb/s WDM system

“…The observation of the Brillouin effect due to an excessive optical power inside the fiber that leads to SBS sidebands has been reported in Ref. 8. The effect of SBS was also observed in a specific configuration of Raman amplifier, as reported in Ref.…”

“…The monopole wideband antenna is also proposed for reconfigurable purposes [8] because of various advantages: low profile, thin and small, ability to produce very wide frequencies, and possession of an omnidirectional pattern. The cognitive communication system requires wideband antennas for spectrum sensing and narrow band antennas for transmission, which has a directional radiation pattern to increase the performance of signal detection.…”