C band single pump photonic crystal fiber Raman amplifier

Abstract

A novel twin-core photonic crystal fiber was proposed to reduce the complexity and cost of fiber Raman amplifiers. By means of a proper design, this fiber could acquire a higher and flatter Raman gain efficiency coefficient curve r R =g R /A eff over a specified band of wavelength than a conventional fiber. A Raman amplifier was designed with this novel twin-core photonic crystal fiber to operate in C band from 1530 nm to 1565 nm. A remarkable improvement over a conventional fiber Raman amplifier was obtained. It was numerically demonstrated that when pumped with a single source, an average gain of 8.7 dB with a fluctuation of less than 0.9 dB is achievable. Raman gain coefficient, Raman gain efficiency, photonic crystal fiber, Raman amplifier Citation:Jiang H M, Xie K, Wang Y F. C band single pump photonic crystal fiber Raman amplifier.Optical amplifier is an important active device in modern fiber communication system to compensate for transmission loss. Among the various types of optical amplifiers, fiber Raman amplifier (FRA) is a key element in WDM system because of its good noise performance, flexible and broad band of amplification [1][2][3]. For the application of FRA in WDM system, a flat gain for a broad band of frequency is a desirable feature [4][5][6]. The flatness of the gain has influence on the optical signal to noise ratio of the system. The resulting difference in signal power level by fluctuant gain can also cause cross-talk between different channels. When ordinary silica fiber is used as the gain medium of an FRA, its intrinsic Raman gain coefficient g R is small and fluctuant. Its relatively flat spectrum has a width of about 2.3 THz. Moreover, the effective overlap core area A eff of a traditional fiber is almost a constant in C band, the resulting Raman gain efficiency coefficient r R =g R /A eff therefore varies significantly with frequency [7]. With such fiber as gain medium, it is not possible to construct a C band FRA with flat gain spectrum by means of a single pump configuration. A flat gain spectrum is achievable with multiple sources to pump simultaneously at different frequencies and powers [8][9][10]. However, such arrangement significantly increases the complexity of the amplifier so that a comprehensive design strategy is needed to carefully allocate the power levels and wavelengths of the multiple pumps, and to take care of the interactions between channels [11−13]. Drawbacks such as higher cost and lower reliability limit the application of FRA in WDM systems. In order to avoid the above-mentioned difficulties, a novel twin-core photo-nic crystal fiber (NPCF) was proposed as the gain medium of an FRA. With this NPCF, a flat gain spectrum can be achieved with a single pump. A NPCF-RA to operate in C band between 1530 nm-1565 nm was designed. Compared with a standard single mode fiber (SSMF) RA, it was numerically demonstrated that this FRA has a marked improvement in performance. Structure and analysis of NPCFDue to the flexibility in the cross-section structure, PCF has many ...

Chromatic Dispersion in Traditional Fiber and Silicon Nanocrystal and Er Doped Fiber Optical Amplifier

“…In order to loss compensation in optical communications, we need optical amplifiers which there are some alternatives such as Si-Nc Er-doped optical amplifier [6][7], semiconductor optical amplifiers (SOA) [8][9][10][11], Erbium doped fiber amplifier (EDFA) [12][13][14][15] and RAMAN amplifiers [16]. Another parameter in optical communication that has very confinement effect is chromatics dispersion [17].…”