C Sigaud

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 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.

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.

Modeling TID Effects in Mach-Zehnder Interferometer Silicon Modulator for HL-LHC Data Transmission Applications

High-speed Mach-Zehnder interferometer silicon modulators were exposed to a total ionizing dose of 1.3 MGy, levels comparable to the worst radiation levels for a tracking detector after 10 years of operation at the High-Luminosity LHC, show a sensitivity to ionizing radiation after exposure to a dose of a few hundred kGy. A physical model to describe the effect of ionizing radiation on the modulators has been developed and is used to predict whether a more radiation-hard modulator can be designed to survive the harshest radiation environments expected at the HL-LHC.

Versatile transceiver development status

The Versatile Link common project is developing optical link architectures and components to be used for readout and control of future HL-LHC experiments. The on-detector opto-electronic module, the Versatile Transceiver (VTRx), is derived from an industry standard module type and is adapted through minimal customization to the requirements dictated by the HL-LHC-specific front-end environment. We present the methods and results of the functional tests carried out on the transceiver components and summarize the development status of the different VTRx variants. Finally we show the results obtained using the packaged VTRx module.

Modelling radiation-effects and annealing in semiconductor lasers for use in future particle physics experiments

Optical link components used in future particle physics experiments will typically be exposed to intense radiation fields during the lifetime of the experiment and the qualification of these components in terms of radiation tolerance is thus required. We have created a model that describes the degradation of the L-I characteristic of a semiconductor laser undergoing irradiation with the annealing processes taken into account. This model can be used to predict the behaviour of a laser being irradiated with the different particle fluxes at different locations inside a particle physics experiment. The robustness of the model has been checked against the experimental data obtained during high-fluence (in excess of 1015 particles/cm2) neutron and pion irradiation testing in 2009 and 2010.

Gamma irradiation of minimal latency Hollow-Core Photonic Bandgap Fibres

Hollow-Core Photonic-Bandgap Fibres (HC-PBGFs) offer several distinct advantages over conventional fibres, such as low latency and radiation hardness; properties that make HC-PBGFs interesting for the high energy physics community. This contribution presents the results from a gamma irradiation test carried out using a new type of HC-PBGF that combines sufficiently low attenuation over distances that are compatible with high energy physics applications together with a transmission bandwidth that covers the 1550nm region. The radiation induced attenuation of the HC-PBGF was two orders of magnitude lower than that of a conventional fibre during a 67.5 hour exposure to gamma-rays, resulting in a radiation-induced attenuation of only 2.1dB/km at an accumulated dose of 940kGy.