F Vasey

The versatile link, a common project for super-LHC

A common project to develop a bi-directional, radiation tolerant, high speed (4.8 Gb/s) optical link for future high energy physics experiments is described. Due to be completed in 2012, it targets the upgrade programs of detectors installed at CERNs Large Hadron Collider (LHC). The development of radiation and magnetic field tolerant opto-electronic devices, fibre and connectors is described. Both Single-Mode and Multi-Mode versions of the system operating respectively at 850 nm and 1310 nm wavelength are proposed. First results at component and system level are presented, based mostly on commercially available devices.

Radiation Damage Studies of Lasers and Photodiodes for Use in Multi-Gb/s Optical Data Links

Neutron and pion irradiation and annealing data from semiconductor lasers and photodiodes for use in 10 Gb/s datalinks are presented. These components are found to be generally more radiation resistant than their older counterparts. Radiation damage in lasers has been modeled to allow extrapolation of the results obtained to the final application.

The Versatile Link common project: feasibility report

The Versatile Link is a bi-directional digital optical data link operating at rates up to 4.8 Gbit/s and featuring radiation-resistant low-power and low-mass front-end components. The system is being developed in multimode or singlemode versions operating at 850 nm or 1310 nm wavelength respectively. It has serial data interfaces and is protocol-agnostic, but is targeted to operate in tandem with the GigaBit Transceiver (GBT) serializer/deserializer chip being designed at CERN. This paper gives an overview of the project status three and a half years after its launch. It describes the challenges encountered and highlights the solutions proposed at the system as well as the component level. It concludes with a positive feasibility assesment and an outlook for future project development directions.

The Versatile Transceiver: towards production readiness

Detectors involved in the upgrade programme of the LHC will need high-speed optical links to transfer readout and control data. The link front-end will be based on a radiation tolerant opto-electronic module, the Versatile Transceiver (VTRx), developed under the Versatile Link project. In this contribution we present a test system and protocol to be used to verify the compliance of the VTRx modules to the specifications, and a Versatile Link demonstrator based on the VTRx and the Gigabit Link Interface Board. Finally, we introduce the Small Footprint VTRx which is being designed for the CMS Tracker upgrade.

The Gigabit Link Interface Board (GLIB), a flexible system for the evaluation and use of GBT-based optical links

The Gigabit Link Interface Board (GLIB) is an evaluation platform and an easy entry point for users of high speed optical links in high energy physics experiments. Its intended use ranges from optical link evaluation in the laboratory to control, triggering and data acquisition from remote modules in beam or irradiation tests. The GLIB is an FPGA-based Advanced Mezzanine Card (AMC) conceived to serve a small and simple system residing either inside a Micro Telecommunications Computing Architecture (μTCA) crate, or on a bench with a link to a PC. This paper presents the architecture of the GLIB, its features as well as examples of its use in different setups.

Versatile Transceiver developments

SLHC experiment upgrades will make substantial use of optical links to enable high-speed data readout and control. The Versatile Link project will develop and assess optical link architectures and components suitable for deployment at SLHC. The on-detector element will be a bidirectional opto-electronic module: the Versatile Transceiver (VTRx) that will be based on a commercially available module type minimally customized to meet the constraints of the SLHC on-detector environment in terms of mass, volume, power consumption, operational temperature and radiation environment. This paper brings together the status of development of the VTRx in terms of packaging, environmental testing and functional testing.

Single-Event Upsets in Photoreceivers for Multi-Gb/s SLHC Data Transmission

A 63 MeV proton beam was used to perform a single event upset (SEU) test on a candidate component for a future high luminosity large hadron collider (HL-LHC) high speed optical. An in-lab error injector was used to show that 1-0 bit errors are caused by the amplifiers response to the large signal caused by a single event transient (SET) in the photodiode.

Single-Event Upset testing of the Versatile Transceiver

The Versatile Transceiver (VTRx) will be deployed on detectors that will be operated at the upgraded HL-LHC where the instantaneous luminosity will be increased by a factor of 5–10 with respect to the nominal LHC. All components housed at the front-ends must thus be immune to single-event-upsets (SEUs) to a level compatible with the correct operation of the detector systems. We report the results of SEU testing of the full VTRx in a proton beam-line.

The versatile transceiver proof of concept

SLHC experiment upgrades will make substantial use of optical links to enable high-speed data readout and control. The Versatile Link project will develop and assess optical link architectures and components suitable for deployment at SLHC. The on-detector element will be bidirectional optoelectronic module: the Versatile Transceiver that will be based on a commercially available module type minimally customized to meet the constraints of the SLHC on-detector environment in terms of mass, volume, power consumption, operational temperature and radiation environment. We report on the first proof of concept phase of the development, showing the steps towards customization and first results of the radiation resistance of candidate optoelectronic components.

Radiation hardness assurance and reliability testing of InGaAs photodiodes for optical control links for the CMS experiment

A radiation hard 80 Mbit/s digital optical link system with 7200 fiber channels is being produced for the CMS Experiment at CERN. A series of tests including radiation damage and thermally accelerated aging have been made to qualify and assure the radiation hardness and reliability of InGaAs photodiodes intended for use in this system.