1. EE 230: Optical Fiber Communication Lecture 14 From the movie Warriors of the Net Optical Time Division Multiplexing

2. OTDM Routing Network

3. Multiplexing Frequency-division multiplexing (FDM) for electrical signals Code-division multiplexing (CDM) for electrical signals Wavelength-division multiplexing (WDM) for optical signals Time-division multiplexing (TDM) for both types

4. Modulation Amplitude modulation Frequency modulation Phase modulation

5. Simple to implement amplitude modulation pulse amplitude modulation amplitude shift keying

6. Economize bandwidth quadrature amplitude modulation single sideband modulation vestigial sideband modulation

7. Economize power double sideband modulation double sideband carrier-suppressed modulation These are easy to modulate but difficult to demodulate

8. Noise resistant phase modulation frequency modulation pulse position modulation pulse code modulation (widely used) amplitude shift keying frequency shift keying

9. Pulse Formats

10. Optical Bit and Packet Interleaving

11. OTDM Bit Interleaved Multiplexer

12. Packet Interleaved Multiplexer

13. Demultiplexing OTDM and soliton systems require RZ format Nonlinear devices required to demultiplex n EO modulators required for 2 n channels Sagnac interferometer (NOLM) uses XPM FWM devices use clock signal as pump, generate new wavelength for “1” bits

14. Synchronizer

15. OTDM Bit Interleaved Demultiplexer

16. Packet Interleaved Demultiplexer

17. Nonlinear Optical Loop Mirror-NOLM

18. Solitons

19. Comparison of Soliton Transmission to other Technologies

20. Effective area of single-mode fiber for 1.2<V<2.405, otherwise A eff =  w 2

21. Peak power for a soliton where  is the pulse width in time and n 2 is the nonlinear index of refraction

22. Example: Corning SMF-28 fiber n CO =1.4504, n CL =1.4447, a=4.1  m, =1550 nm. NA=? NA=0.13. k=? k=2  / =4.05x10 6 m -1. V=? V=2.16. w/a=? w/a=1.19. w=? w=4.87  m. A eff =? A eff =7.46x10 -11 m 2

23. Example, continued D=19 ps/km-nm, n 2 =3.18x10 -20 m 2 /W,  =20 ps. P=? D=1.9x10 -5 s/m 2 3 =3.72x10 -18 m 3  2 =4x10 -22 s  2 =9.87 P=0.108W=108 mW—pretty high!