Component Prototypes towards a Low-Latency, Small-form-factor Optical Link for the ATLAS Liquid Argon Calorimeter Phase-I Trigger Upgrade

TL;DR

This paper introduces several innovative component prototypes for a low-latency, compact optical link tailored for the ATLAS Liquid Argon Calorimeter trigger upgrade, achieving high data rates and minimal latency.

Contribution

It presents the design and testing of a novel dual-channel optical transmitter, VCSEL driver ASIC, serializer ASIC, and encoder ASIC, all optimized for low latency and small size.

Findings

Achieved data rates up to 8 Gbps per channel.

Estimated total link latency below 57.9 ns.

Prototype size is 45 mm x 15 mm x 6 mm.

Abstract

This paper presents several component prototypes towards a low-latency, small-form-factor optical link designed for the ATLAS Liquid Argon Calorimeter Phase-I trigger upgrade. A prototype of the custom-made dual-channel optical transmitter module, the Miniature optical Transmitter (MTx), with separate transmitter optical sub-assemblies (TOSAs) has been demonstrated at data rates up to 8 Gbps per channel. A Vertical-Cavity Surface-Emitting Laser (VCSEL) driver ASIC has been developed and is used in the current MTx prototypes. A serializer ASIC prototype, operating at up to 8 Gbps per channel, has been designed and tested. A low-latency, low-overhead encoder ASIC prototype has been designed and tested. The latency of the whole link, including the transmitter latency and the receiver latency but not the latency of the fiber, is estimated to be less than 57.9 ns. The size of the MTx is 45 mm x 15 mm x 6 mm.