Sensitivity Calculations of High-Speed Optical Receivers Based on Electron-APDs

Vladimir Shulyak,Majeed M Hayat,Jo Shien Ng

doi:10.1109/jlt.2019.2950804

Vladimir Shulyak, Majeed M Hayat + Show 1 more

Open Access

https://doi.org/10.1109/jlt.2019.2950804

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Abstract

Sensitivity of high-speed optical receivers is heavily influenced by the performance of the optical detectors used in the receivers, the data rate, and the target bit-error-rate (BER). A simulation model for sensitivity of optical receivers based on electron-avalanche photodiodes (e-APDs) is presented. It allows for the optimization of avalanche width and operating voltage to achieve the optimum receiver sensitivity for given bit rate and target BER. The effects modelled include inter-symbol interference (ISI), various dark current components (tunnelling, diffusion, and generation), current impulse duration, avalanche gain, and amplifier's noise. The model was demonstrated through simulations of Indium Arsenide (InAs) e-APDs. For $10^{-12}$ target BER, the receiver's sensitivities were found to be −30.6, −22.7, −19.2, and −16.6 dBm, for 10, 25, 40, and 50 Gb/s data rate, respectively. Desirable avalanche properties of InAs e-APDs are counteracted by detrimental effects of high dark currents. Hence InAs e-APDs with lower dark currents are required to be more competitive with other optical detector technologies for high-speed optical receivers. The data reported in this article is available from the ORDA digital repository (DOI: 10.15131/shef.data.9959468).

Highlights

A VALANCHE photodiodes (APDs) are widely used optical detectors in the domain of high-speed optical receivers for long-haul optical communication systems
Several APD-related characteristics determine the performance of APD-based optical receivers, including (i) the excess noise factor; (ii) the stochastic avalanche duration, which increases with gain and decreases the APD’s speed; (iii) the APD’s dark current
In this paper we present a model that can be applied to any electron-avalanche photodiodes (e-APDs), capturing effects which include; inter-symbol interference (ISI), tunnelling current, diffusion current, generation current, avalanche pulse duration, avalanche gain, and amplifier noise

Summary

INTRODUCTION

A VALANCHE photodiodes (APDs) are widely used optical detectors in the domain of high-speed optical receivers for long-haul optical communication systems. Several APD-related characteristics determine the performance of APD-based optical receivers, including (i) the excess noise factor; (ii) the stochastic avalanche duration, which increases with gain and decreases the APD’s speed; (iii) the APD’s dark current. Analytical simulation models of APD-based receivers have been developed to determine their sensitivity [1]–[3] These models assume both electrons and holes will impact ionize ( the case for important avalanche materials for optical receivers, such as InP and InAlAs), whereby the random avalanche buildup time within the APD is not deterministic. They cannot be applied without modification to an important sub-class of APDs known as an electron-APDs (e-APD). Sensitivity calculations obtained using our model for InAs e-APDs, which have excellent excess noise characteristics but relatively high dark currents, are reported here to demonstrate the model’s functionality

MODEL DETAILS

Modification of the Model for Optical Receivers based on e-APD

Model Parameters for InAs e-APDs

Sensitivity at Different Avalanche Widths and Bit Rates

CONCLUSION