Optical Networks: A Practical Perspective - Part 23 pdf

... where a fraction 1 - x of the Ga atoms in GaAs are replaced by In atoms. In l-xGaxAsyPl_y is a quaternary compound semiconductor material where, in addition, a fraction 1 - y of the As atoms are ... multiplicative gain of an APD can be made quite large and even infinite a condition called avalanche breakdown. However, a large value of Gm is also accompanied by a l...

Ngày tải lên: 02/07/2014, 12:21

... user-to-network interface (UNI), 382, 385, 523 valence band, 161 variable optical attenuator (VOA), 213 Vernier effect, 231 vertical cavity surface-emitting lasers (VCSELs), 17 3-1 74 advantages, ... signal formats, 24 0-2 42 DC balance and, 241 non-return-to-zero (NRZ), 24 0-2 42 return-to-zero (RZ), 24 0-2 42 See also on-off keying (OOK) modulation signaling inte...

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... may accept data at any bit rate and any protocol format within these limits. It may also be able to carry analog data. Transparency in the network provides several advantages. An operator can ... network. Transparency type Parameter Fully transparent Practical Nontransparent Analog/digital Both Digital Digital Bit rate Arbitrary Predetermined maximum Fixed Framing protocol Arbitrary...

Ngày tải lên: 02/07/2014, 12:21

... generation of systems. A major advantage of EDFAs is that they are capable of amplifying signals at many wavelengths simultaneously. This provided another way of increasing the system capacity: ... of amplification (such as Raman amplification, a topic that we will cover in Chapter 3) that complement EDFAs and hold the promise to open up other fiber bands such as the S-band and the U...

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... energy from a lower-wavelength signal to a higher-wavelength signal is a fundamental effect that is also the basis of optical amplification and lasers. The energy of a photon at a wavelength ... generated as a result of nonlinear dielectric polarization at 3co0 has a propagation constant 3fi0, where/30 = fl(oo0) is the propagation constant at the angular frequency coo. In...

Ngày tải lên: 02/07/2014, 12:21

... Laser Periodic pulses AAAAA 1 I (a) Modulator] I Electrical NRZ data 0 0 1 1 I I Modulated pulses 1 0 0 1 1 A AA CW signal Periodic pulses AAAAA I stage 1 I Two-stage modulator ... device, a polarization maintaining fiber is used between the laser and the modulator. The EA modulator is an attractive alternative to lithium niobate modulators because it can be fabricate...

Ngày tải lên: 02/07/2014, 12:21

... wavelengths that they can handle at their inputs and outputs. A fixed-input, fixed-output device always takes in a fixed-input wavelength and converts it to a fixed-output wavelength. A variable-input, ... (regeneration with reshaping and retiming). 3.8.2 Optical Gating Optical gating makes use of an optical device whose characteristics change with the intensity of an input...

Ngày tải lên: 02/07/2014, 12:21

... that can provide total chromatic dispersion of between -3 40 and -1 360 ps/nm are commercially available. An 80 km length of standard single-mode fiber has an accumulated or total chromatic dispersion, ... want a grating that introduces a large amount of chromatic dispersion over a wide bandwidth so that it can compensate for the fiber chromatic dispersion over a large length...

Ngày tải lên: 02/07/2014, 12:21

... signal-to-noise ratio at the end of the path will also fluctuate with time, and careful attention needs to be paid to maintain the total PDL on the path to within acceptable limits. An example ... effect by a factor of 2. To calculate the effect of SRS in a multichannel system, following [Chr84], we approximate the Raman gain shape as a triangle, where the Raman gain coefficient as...

Ngày tải lên: 02/07/2014, 12:21

... Thus, in all but one cell, the AAL-5 payload is equal to the 48-byte ATM payload, and AAL-5 has lower overhead compared to AAL-1. Also note that AAL-5 provides error detection for its payload through ... layer. Functions of ATM ATM data can either be transmitted from an ATM user to an ATM network across a user-to-network interface (UNI) or the data can be transmitted across a networ...

Ngày tải lên: 02/07/2014, 12:21