Design Considerations for Energy Efficient DWDM PAM4 Transceivers Employing Avalanche Photodiodes. Issue 9 (20th July 2020)

• Record Type: Journal Article
• Authors: Kumar, Ankur; Huang, Zhihong; Zeng, Xiaoge; Wang, Binhao; Liang, Di; Sorin, Wayne; Fiorentino, Marco; Beausoleil, Raymond G.; Palermo, Samuel
• Is Part Of: Laser & photonics reviews. Volume 14:Issue 9(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-07-20
• Subjects: avalanche photodiodes -- energy efficiency -- link budget -- optical modulation amplitude sensitivity -- pulse‐amplitude modulation -- silicon photonics transceiver -- transimpedance amplifier; Lasers -- Periodicals; Photonics -- Periodicals; Lasers -- Périodiques; Photonique -- Périodiques; 621.36
• DOI: 10.1002/lpor.202000142
• Languages: English
• ISSNs: 1863-8880

Abstract

Abstract: An effective approach to increase per‐fiber bandwidth is to combine per‐wavelength four‐level pulse amplitude modulation (PAM4) with dense wavelength division multiplexing (DWDM). Silicon photonic transceivers based on microring resonator modulators and drop filters can allow for an efficient realization of this. Utilizing avalanche photodiodes (APDs) in the receiver front‐ends of these transceivers can significantly improve sensitivity, allowing for reduced source laser power and overall improved power efficiency. This paper analyzes the optical‐modulation amplitude (OMA) sensitivity of these APD‐based PAM4 receivers in a silicon photonic DWDM link. A comprehensive link budget is considered that takes into account various system losses and relevant noise sources. Modeling with a developed APD that has a maximum 230 GHz gain‐bandwidth product predicts sensitivity improvements at 32 to 64 Gb s −1 PAM4 ranging from 9.8 to 12 dB relative to a conventional p‐i‐n photodiode. Scaling the APD gain‐bandwidth to 310 GHz allows support of 112 Gb s −1 with −13.2 dBm OMA sensitivity at a BER of 2.4 × 10 − 4 with an APD gain of 10. Utilizing the presented architecture, link budget analysis predicts a 9.5x reduction in laser power with APDs and that 38 mW source laser optical power can support a four‐channel DWDM link operating at an aggregate 448 Gb s −1 data rate. Abstract : Herein, the OMA sensitivity of APD‐based PAM4 receivers in a silicon photonic DWDM link is analyzed. Scaling the APD gain‐bandwidth to 310 GHz allows support of 112 Gb s −1 with −13.2 dBm OMA sensitivity at a BER of 2.4 × 10 − 4 with an APD gain of 10. A comprehensive link budget considering various system losses and noise sources predicts 9.5x reduction in laser power with APDs.