  The ATLAS phase-I upgrade aims to enhance event trigger performance in the
Liquid Argon (LAr) calorimeter and the forward muon spectrometer. The trigger
signals are transmitted by optical transceivers at 5.12 Gbps per channel in a
radiation field. We report the design, quality control in production and ageing
test of the transceivers fabricated with the LOCld laser driver and multi-mode
850 nm vertical-cavity surface-emitting laser (VCSEL). The modules are packaged
in miniature formats of dual-channel transmitter (MTx) and transceiver (MTRx)
for the LAr. The transmitters are also packaged in small form-factor pluggable
(SFP) for the muon spectrometer. In production, the LOCld chips and VCSELs in
TOSA package were examined before assembly. All of the modules were tested and
selected during production for quality control based on the eye-diagram
parameters measured at 5.12 Gbps. The yield is 98 % for both the MTx and MTRx
on a total 4.7k modules. The uniformity of transmitter channels of a MTx was
assured by choosing the TOSA components with approximately equal light powers.
The ageing effect is monitored in burn-in of a small batch of transmitter
modules with bit-error test and eye-diagrams measured periodically. The
observables are stable with the light power degradation within 5 % over a
period of more than 6k hours.
