High Bit-Rate Receivers, Transmitters and Electronics

The explosive advancement in the optical transmission in recent years has created an unlimited appetite for high speed, high capacity system. In order to at least half satisfy the demand, numerous studies have been presented in the industry for achieving 40 Gb/s and beyond, high bit rate, dense DWM system capability, exceeding multi-Terabit/s. In addition to so-called long haul transmission needs, very short reach (VSR) and short haul application needs have been increasing quickly. Typical requirements, including chirp, extinction ratio, wavelength stability are not always considered as important factors in these applications, but size, power dissipation and cost are the top priorities. In order to meet these very different needs, several different transmitter configurations are considered. In addition to the typical modulators that have been used, including Electro-Absorption (EA), Electro-Absorption Modulator Integrated Laser (EML), Mach-Zehnder (MZ), and Lithium Niobate (LN) type, directly modulated 10GB/s Fabri-Perot and Distributed Feedback (DFB) lasers are being considered for low cost VSR and short haul needs. In this chapter, different style transmitter designs are introduced. They are categorized in terms of the purposes (cost, transmission media, size, etc.) and its applications are discussed. Transmitter examples are shown, including 10GB/s laser transmitter, integrated electro-absorption modulator integrated laser (EML) and 40GB/s Optical Time Division Multiplex (OTDM) and Electronic Time Division Multiplex (ETDM) prototype systems, which consists of transmitter, Erbium Doped Fiber Amplifiers (EDFA) and receiver. Much of the attention is paid on the stable circuit design. Finally, transmitters with output formats other than NRZ are described. These bench-top research systems have been built to achieve long distance and high spectral efficiency in DWDM transmission.