Analysis and Design of Transimpedance Amplifiers for Optical Receivers

Chapter 1Introduction

After a brief description of the components that make up an optical receiver and transmitter, we discuss how digital and analog information is modulated on a lightwave. We explain the difference between continuous-mode and burst-mode transmission and summarize applications and standards for both transmission modes.

1.1 Optical Transceivers

Figure 1.1 shows the block diagram of a conventional optical receiver and transmitter. On the transmitter side, a coder and/or scrambler preprocesses the parallel input data. Optionally, the coder adds redundancy to permit error detection and correction at the receiver end. These coding steps condition the data for the subsequent serial transmission through a band-limited and noisy channel. Next, a multiplexer (MUX) serializes the -bit wide parallel data into a single high-speed bit stream. A clock multiplication unit (CMU) synthesizes the necessary bit-rate (or half bit-rate) clock from the times slower word clock (or another convenient reference clock). After that, a transmit equalizer (TXEQ) may be used to shape (predistort) the serial high-speed signal in preparation of the band-limited channel. Finally, a laser driver or modulator driver drives the corresponding optoelectronic device. The laser driver modulates the ...