fibre optic power transmission lines

Ngày tải lên: 15/10/2013, 16:24

Ngày tải lên: 13/12/2013, 01:16

... Calculate the transmission distance over which the optical power will attenuate by a factor of 10 for three fibers with losses of 0.2, 20, and 2000 dB/km. Assum- ing that the optical power decreases ... 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 ... Gb/s. Chapter 3 is devoted to a complete description of optical transmitters. 1.4.3 Optical Receivers An optical receiver converts the optical signal received at the output end of the opti- cal...

Ngày tải lên: 24/12/2013, 01:16

... loss mechanisms in optical fibers. 2.5.1 Attenuation Coefficient Under quite general conditions, changes in the average optical power P of a bit stream propagating inside an optical fiber are governed ... 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...

Ngày tải lên: 24/12/2013, 01:16

... 3. OPTICAL TRANSMITTERS acts as a bandpass filter of bandwidth Ω R to spontaneous-emission fluctuations. At a given frequency, RIN decreases with an increase in the laser power as P −3 at low powers, ... from the standpoint of their application in optical communication systems [20]. 3.2.1 Power Current Characteristics It is easy to estimate the internal power generated by spontaneous emission. At ... noise. From Eq. (3.5.30), SNR =[C pp (0)] −1/2 . At power levels above a few milliwatts, the SNR exceeds 20 dB and improves linearly with the power as SNR =  ε NL R sp τ p  1/2 ¯ P. (3.5.33) The...

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 ... the noise added at optical amplifiers. The minimum average optical power required by the receiver increases because of such nonideal conditions. This increase in the average received power is referred ... to as the power penalty. In this section we focus on the sources of power penalties that can lead to sensitivity degradation even without signal transmission through the fiber. The transmission- related...

Ngày tải lên: 24/12/2013, 01:16

... cable carries the multichannel optical signal throughout the area of service. Distribution is done by using optical taps, which divert a small fraction of the optical power to each subscriber. A ... the optical pulse remains Gaussian, but its peak power is reduced by a pulse-broadening factor given by Eq. (2.4.17). If we define the power penalty δ d as the increase (in dB) in the received power ... uses an optical bus to distribute the signal to 10 users. Each optical tap couples 10% of the power to the user and has 1-dB insertion loss. Assuming that the station 1 transmits 1 mW of power...

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 ... 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 saturation power P s depends on ... (6.1.15), 246 CHAPTER 6. OPTICAL AMPLIFIERS Figure 6.12: Variation of amplifier gain G 0 with pump power P 0 in a 1.3-km-long Raman am- plifier for three values of the input power. Solid lines show the theoretical...

Ngày tải lên: 21/01/2014, 06:20

... technique, a power 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 ... 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 ... case in which a tunable optical filter is used to select a single channel among the N channels incident on it. If the optical filter is set to pass the mth channel, the optical power reaching the photodetector ... considerable power in the FWM component, especially at high channel powers. In the case of equal channel powers, P F increases as P 3 ch . This cubic dependence of the FWM component limits the channel powers...

Ngày tải lên: 21/01/2014, 06:20

... curves show the contribution of the Gordon–Haus jitter alone. Optical filters help in reducing both types of timing jitter and permit transmission of 10-Gb/s solitons over more than 20 Mm. In the ... semiconductor laser, followed by an optical bandpass filter [52]. Phase modulation generates frequency modulation (FM) sidebands on both sides of the carrier frequency, and the optical filter selects the ... stream in the NRZ format, to convert the CW output of a DFB laser into an optical bit stream in the RZ format [53]. Although optical pulses launched from such transmitters typically do not have the...

Ngày tải lên: 21/01/2014, 06:20

... loss is equivalent to a 3-dB power penalty. Balanced receivers use all of the signal power and avoid this power penalty. At the same time, all of the local-oscillator power is used by the balanced ... local-oscillator power is used effec- tively. A single-port receiver such as that shown in Fig. 10.1 rejects half of the signal power P s (and half of P LO ) during the mixing process. This power loss ... seen by the detector (as the detector responds only to the optical power) and are not of major concern except for the chirp-induced power penalty discussed in Section 5.4.4. The situation is...

Ngày tải lên: 21/01/2014, 06:20

Ngày tải lên: 14/02/2014, 00:20

... J. Power transmission and distribution/Anthony J. Pansini 2nd ed. p. cm. Includes index. ISBN: 0-88173-503-5 (print) — 0-88173-504-3 (electronic) 1. Electric power transmission. 2. Electric power ... apparent power. From Figure 1-5 Power factor = wa tt s EI = cos θ where E = effective voltage, I = effective current, and θ is their angular displacement in phase. Figure 1 -5. Power Factor A power ... distribution (and transmission) system which is dependent on current capacity. For the same current and the same voltage, the power delivered is directly proportional to the power factor. Balance On...

Ngày tải lên: 18/02/2014, 22:20

Ngày tải lên: 04/04/2014, 11:52

Ngày tải lên: 01/05/2014, 08:23

Ngày tải lên: 27/06/2014, 05:20

Ngày tải lên: 27/06/2014, 08:20

Ngày tải lên: 27/06/2014, 17:20

... CRC Press LLC Sub -Transmission Lines Typical sub -transmission lines interconnect the high-voltage substations with distribution stations within a city. The voltage of the subtransmission system ... maximum length of sub -transmission lines is in the range of 50–60 miles. Most subtransmission lines are located along streets and alleys. Figure 4.8 shows a typical sub -transmission system. This ... two lines. This assures that the outage of a single line does not cause loss of power to any customer. For example, the Aqua Fria generating station (marked: Power plant) has three outgoing lines. ...

Ngày tải lên: 05/03/2014, 16:20