Optoelectronic transponder hybrid circuit for 10 Gb/s applications: design, implementation and experimental characterization

This paper describes the design, implementation and performance evaluation of two hybrid prototypes of 10 Gb/s wavelength adapters, developed for WDM network and system applications. These prototypes make use of external modulation of C-band CW DFB lasers, based on either LN-MZM (lithium niobate Mach-Zehnder modulator) or EAM (Electro-Absorption Modulator) techniques. The transponder basically consists of three main blocks: the receiver, the clock and data recovery circuitry and the transmitter. The receiver makes use of an optoelectronic converter and an AGC (Automatic Gain Control) amplifier that may operate either in 1 R, 2 R or 3 R modes. Our prototypes permit that the signal becomes practically free from errors for a distance up to 50 km in a standard fiber with no dispersion compensation. Particular attention is dedicated to some important design issues, such as the full assessment of connectivity and packaging problems posed by low cost multilevel hybrid circuits carrying very high speed (10 Gb/s, 40 Gb/s and beyond) broadband electrical signals and the comparison between the available external modulation techniques.