The VTRx+, an Optical Link Module for Data Transmission at HL-LHC

Optical data transmission will remain a key enabling technology for the upgrading detectors at HL-LHC. In particular the inner tracking detectors will require low-mass, radiation tolerant optical transmit- and receive modules for tight integration in the detector front-ends. We describe the development of such a module, giving details of the design, functional and environmental performance and showing the feasibility of achieving small size, low-mass, and low-power operation.