In this chapter we consider issues related to the design of optical receivers. As signals travel in a fiber, they are attenuated and distorted, and it is the function of the receiver circuit at the other side of the fiber to generate a clean electrical sig. In this chapter we consider issues related to the design of optical receivers. As signals travel in a fiber, they are attenuated and distorted, and it is the function of the receiver circuit at the other side of the fiber to generate a clean electrical signal from this weak, distorted optical signal. An optical receiver consists of an optical det. It is well known that in order to maximize the signal-to-noise ratio (SNR) of a communication system, it is crucial to improve the SNR at the first stage when the signal is weakest. In other words, any noise added to a signal at the first stage will be amplified by subsequent stages, and thus it will be hard (if not impossible) to remove. For fiber. As discussed earlier, an optical receiver typically requires a clock and data recov-ery (CDR) circuit to extract the clock signal from the received serial data. More-over, the extracted clock can be used to retime the serial data itself, thus reducing the amount of jitter that is present in the data. Intuitively, we expect that there should be a. The receivers we have been discussing so far can be categorized as continuous mode or CW because the received optical power remains relatively constant. Thus, it is easy for the receiver feedback loops to catch up and adjust with any long-term change in power. However, there is a class of applications where the re-ceived power can change in a very. So far we have not explicitly discussed the implications of burst mode traffic on TIA operation. In practice, TIAs also need to be modified to accommodate burst mode traffic. In a BMR, the primary factor that is affected in a TIA is the AGC loop. As noted before, the AGC loop increases the dynamic range of the TIA and it does so through a feed.
