International Journal of Electrical and Computing Engineering Vol. 1, Issue. 1, July – 2014 ISSN (Online): 2349-8218 17 Study on 20 and 50 Gbps Soliton Transmission in Conventional Single Mode Fiber (SMF) Mr. Vigneswaran 1 , Mr. Mahendran 2 1,2 Assistant Professor, Dept of Electronics and Communication Engineering, Alagappa Chettiar College of Engineering and Technology, Karaikudi, INDIA Abstract - In this paper we study the soliton transmission in single mode fiber for the 20 and 50 Gbps. Each bitrate of the system confines its own signal power and induce the nonlinearity effect. We also measure the chirping effect of the pulse before and after transmitting along the fiber for the different levels of input power and dispersion effect on soliton pulse under the GVD and second order non linear effect pulse propagation. The order of soliton is calculated with respect to periodical distribution along the fibre, here the fundamental period of soliton is analyzed. As like that other higher order soliton with account of dispersion length and non linear length can be related as in case of fundamental solitons. The soliton transmission system can be designed using photonic crystal fibre as like in single mode fibres with this same system modeling. Keywords – Soliton pulse, GVD, bitrate I. INTRODUCTION In a long haul communication link, single mode fiber is mostly preferred due to less impact of dispersion effect rather than the multimode fiber. In conventional single mode fiber, for the higher order bitrate data we require high level of powers in order of 100mw, due to the high intensity input pulse there is sum criteria of existing non linear effect like self phase modulation and four wave mixing, here we consider both the non linear effect (Kerr effect) and group velocity dispersion effect to produce a narrow width with high peak power intensity pulse is called as soliton [1]. Soliton is a kind of pulse which has a packet of energy to carry the information over long haul communication. When we managing the group velocity dispersion (anomalous dispersion regime), and self phase modulation (positive dispersion regime), we can create a soliton pulse [2,3]. The effect of soliton communication is desirable for long distance communication system with high data rate of the system [4,5]. In a optical communication system soliton pulse are narrow with high intensity optical pulse that retain their shape through the interaction of balancing pulse dispersion with the non linear properties of an optical fiber. The family of soliton pulse that do not change in shape called fundamental solution and there that undergo shape changes are called high order solitons [6,7]. When a narrow high intensity pulse propagating along the medium with anomalous GVD parameter which counteracts the chip produced by the Kerr effect [8]. GVD retards the low frequencies in the front of the pulse and influence the high frequencies at the back end of the pulse. The result is soliton pulse change neither its shape nor its spectrum as they traveling along the fiber. II. SYSTEM MODELING Two kind of bit rate is analyzed at 20 Gbps and 50 Gbps. Both the bit rate of the system has its own input signal power and same non linear index medium. Consider the bit rate 20 Gbps, so the bit slot is 50ns from that the half power pulse with is calculated as 25 ps so T FWHM is 25 ps. The soliton pulse have a relation for full width half maximum to the initial pulse width as T FWHM = 2ln (1+√2) T o ≈ 1.763 T o The original pulse has time slot of T o = 14.1803ps. The other terms for calculating to find the input signal power are dispersion length (L D ), dispersion coefficient (ȕ 2 ), Non- linear length (L NL ) can be calculated as (1) (2) (3) Where is 20.1 PS 2 /km, A eff = 80 μ m 2 , n 2 = 3 X 10 -20 m 2 /w Using the above relation we can calculate the input power as 65.76 mw for 20 Gbps. In similar way for the 50Gbps system, the input power is calculated as 411.0144mw (initial pulse width of T 0 = 5.67).