fibre optic transmission lines

... of an optical transmitter is to convert the electrical signal into optical form and to launch the resulting optical signal into the optical fiber. Figure 1.11 shows the block diagram of an optical ... applies to a fiber -optic communication system, the only difference being that the communication channel is an optical fiber cable. The other two components, the optical transmitter and the optical receiver, ... PD24, Proc. Optical Fiber Commun. Conf., Optical Society of America, Washington, DC, 2001. [27] G. Vareille, F. Pitel, and J. F. Marcerou, Paper PD22, Proc. Optical Fiber Commun. Conf., Optical Society...

Ngày tải lên: 24/12/2013, 01:16

... used in the optical domain. It can also be used for wavelength conversion. FWM in optical fibers is some- times used for generating a spectrally inverted signal through the process of optical phase ... fiber -optic communications. Several books devoted entirely to optical fibers cover numerous advances made in their design and understanding [12]–[21]. This chapter focuses on the role of optical ... silica fibers for optical communications became practical only when losses were reduced to an acceptable level during the 1970s. With the advent of optical amplifiers in the 1990s, transmission distances...

Ngày tải lên: 24/12/2013, 01:16

... recombination time associated with stimulated emission. Most fiber -optic communication systems use semiconductor lasers as an optical source because of their superior performance compared with ... uniform in all directions. 3.2 Prove that the 3-dB optical bandwidth of a LED is related to the 3-dB electrical bandwidth by the relation f 3dB (optical)= √ 3 f 3dB (electrical). 3.3 Find the composition ... limit the performance of optical communication systems, especially when β 2 C > 0, where β 2 is the dispersion parameter and C is the chirp parameter. Even though optical pulses emitted from...

Ngày tải lên: 24/12/2013, 01:16

... the average optical power received. The average optical power corresponding to a BER of 10 −9 is a measure of receiver sensitivity. Figure 4.23 shows the receiver sensitivity measured in various transmission ... 1980. [4] S. R. Forrest, in Optical Fiber Telecommunications II, S. E. Miller and I. P. Kaminow, Eds., Academic Press, San Diego, CA, 1988, Chap. 14. [5] B. L. Kasper, in Optical Fiber Telecommunications ... Diego, CA, 1988, Chap. 18. [6] S. B. Alexander, Optical Communication Receiver Design, Vol. TT22, SPIE Press, Bellingham, WA, 1995. [7] R. J. Keyes, Optical and Infrared Detectors, Springer, New...

Ngày tải lên: 24/12/2013, 01:16

... and then converts it back into optical form by modulating an optical source. Fiber losses can also be compensated by using optical amplifiers, which amplify the optical bit stream directly without ... cases. Deformation of the optical bit stream during its transmission through the optical fiber is calculated by solving the NLS equation (5.3.1). The noise added by optical amplifiers should be ... dispersion-limited transmission distance is shorter than the loss-limited distance of Eq. (5.2.1), the system is said to be dispersion- limited. The dashed lines in Fig. 5.4 show the dispersion-limited transmission...

Ngày tải lên: 24/12/2013, 01:16

... cascaded chain of optical amplifiers. 6.5.1 Optical Preamplification Optical amplifiers are routinely used for improving the sensitivity of optical receivers by preamplifying the optical signal before ... introducing wavelength-selective losses through an optical filter. The basic idea behind gain flattening is quite simple. If an optical filter whose transmission losses mimic the gain profile (high ... (6.1.1) where g 0 is the peak value of the gain, ω is the optical frequency of the incident signal, ω 0 is the atomic transition frequency, and P is the optical power of the signal being amplified. The...

Ngày tải lên: 21/01/2014, 06:20

... splitter at the receiver splits the received optical signal into several branches. Fiber -optic delay lines introduce variable delays in different branches. The optical signal in each branch is converted ... DCF provides an all-optical technique that is capable of compensating the fiber GVD completely if the average optical power is kept low enough that the nonlinear effects inside optical fibers are ... Management It should be clear from Chapter 6 that with the advent of optical amplifiers, fiber losses are no longer a major limiting factor for optical communication systems. Indeed, mod- ern lightwave systems...

Ngày tải lên: 21/01/2014, 06:20

... signal is in the electric form for electro -optic demultiplexing but consists of an optical pulse train for all-optical demultiplexing. The electro -optic technique uses several MZ-type LiNbO 3 modulators ... distribution, and transmission losses. Optical amplifiers are used to compensate for such losses but not all channels are amplified by 8.1. WDM LIGHTWAVE SYSTEMS 333 Table 8.1 High-capacity WDM transmission ... modulators. The electro -optic technique also requires a large number of expensive components, some of which need high drive voltage. Several all-optical techniques make use of a nonlinear optical-loop mirror...

Ngày tải lên: 21/01/2014, 06:20

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Ngày tải lên: 27/06/2014, 17:20

... Internet Baey, Fladenmuller – Subject 1 1/13 MOB TME Subject 1 – Signal Transmission SIGNAL AND WAVES PROPAGATION Data transmission on a physical support is the result of the propagation of a ... power of the signal are typically carried out on a logarithmic scale. The power is Watts in a radio transmission is therefore typically expressed in the relative value of decibels compared to a milliwatt ... walls penetration of 16 dB per level and an attenuation exponent from 31. Calculate the maximum transmission range for the same signal power than previously. You consider antennas located at the...

Ngày tải lên: 17/09/2012, 09:13

... groups). /43/4 5/4 7/4 A 1101 00 10 Master of Computer Science 1 - MOB Mobile Internet and Surrounding 2/18 – Base band transmission: it corresponds to transmission on channel of the low-pass type of a centered spectrum signal around ... signals of "square" form. – Carrier frequency transmission: when the channel is of band-pass type as in the case of the hertzian transmission, it is essential to transpose the signal ... Mobile Internet and Surrounding 8/18 The modern transmission systems call upon the digital techniques which allow between others offering a better transmission quality. The modulating signal comes...

Ngày tải lên: 17/09/2012, 09:13

... duration T c of transmission of a chip is m time lower than the duration T b of a bit. Master of Computer Science 1 - MOB Mobile Internet and Surrounding 1/10 Subject 4 MOB sujet 4 Transmission ... transmit a bit to “0”, the station sends the opposite of its sequence chip. The duration T c of transmission of a chip is m time lower than the duration T b of a bit. Example: let us suppose...

Ngày tải lên: 17/09/2012, 09:13

... number of cycles to failure N, the fibre mixes exhibit superior performance. The fatigue lines for the fibre mixes are always higher than the control but these lines converge at high number of ... without the fibres (control mix) and those reinforced with fibres. Figure 5 Restriction of crack propagation by fibers (after Tons and Krokosky, 1963) Specimens containing the fibres cracked ... cracked over a wider area than those without fibres, demonstrating the load spreading ability of the fibres in the mix. It is conceivable that the fibres can act as crack arresters in the bituminous...

Ngày tải lên: 01/04/2013, 22:43

... used are shown in Table 1. 4. 2 Synthetic Fibres Two types of synthetic fibres namely polypropylene and polyester were used in this study. The fibres were used as a partial replacement of ... connectivity of the voids. The presence of the fibres also suggests an increase in the connectivity of the voids as the porous nature of the fibres gave a continuous channel (path) of void ... lower porosity than the fibre incorporated mixes, thus justifying its behavior as in Figure 5 of moisture damage that was noted from the control mix. The polyester fibre modified mixes also...

Ngày tải lên: 01/04/2013, 22:43