Reliability Of Vertical-Cavity Surface-Emitting Laser Arrays With Redundancy

This paper describes theoretical reliability analysis of a system containing n optical ports in which each optical port contains m redundant vertical-cavity surface-emitting lasers. We study the wearout failure statistics, modelled with lognormal distribution, for three different chip-level integration approaches: ( A ) each laser on its own chip, resulting in m center dot n chips, ( B ) m redundant lasers associated with one channel are on a single chip, resulting in n chips, and ( C ) all m center dot n lasers integrated on a single chip. We present a model that includes the run-to-run reliability parameter fluctuation and find that the three integration schemes consistently exhibit MTTF( C ) >= MTTF( A ) >= MTTF( B ) for lognormal distribution shape parameters observed in commercial vertical-cavity surface-emitting lasers. We also provide analytic approximations for the failure statistics for all three integration approaches enabling straightforward calculation of the failure statistics for any redundancy and channel number.