The analog local loop: a growing revolution in optical transmission

Optimum Photodetection in Subcarrier Multiplexed Lightwave Systems

“…Although the superior characteristics of the APD in high bit rate digital optical systems is well established, its merits in SCM lightwave transmission have not previously been clarified, since initial proposals that the nonideal excess noise factor can in fact degrade the output signal to noise ratio [2]. APD detectors have nevertheless been employed to advantage in specific SCM receivers [3], however a detailed analysis of their performance in general SCM receiver structures has not been reported. This paper evaluates the optimum APD gain and relative sensitivity performance of PIN and…”

“…The optimum APD avalanche gain, the resulting minimum required photocurrent for a given system carrier to noise ratio, and the sensitivity performance of PIN and APD receivers, are obtained. Results show that APD detection provides a sensitivity improvement in excess of 8 dB for a range of receiver noise levels from 50 ohm receivers to tuned configurations, enabling a significant increase in SCM power budget and distribution capacity.APD receivers over a range of receiver input equivalent noise levels, including tuned [4,5], untuned, an 50 ohm [3,6], receiver configurations. The results are applicable to the selection of the optimum photodetection characteristics in SCM receivers, to maximise sensitivity and signal distribution capacity.…”

“…APD receivers over a range of receiver input equivalent noise levels, including tuned [4,5], untuned, an 50 ohm [3,6], receiver configurations. The results are applicable to the selection of the optimum photodetection characteristics in SCM receivers, to maximise sensitivity and signal distribution capacity.…”