Intermittent loss of light output and switching behavior in AlGaAs lasers modulated at 90 mbit/s

An intermittent loss of light output in AlGaAs lasers modulated at 90 Mbit/s is investigated and is attributed to a parallel intermittent shunt that switches between a resistive and conducting state. The shunt is associated with the presence of In contamination on the sidewalls of the laser chip. A calculation of the switching time based on conducting filaments through In
1-x
O
x
is consistent with the pulsed operation of the laser in testing. This shunt is avoided if bonding techniques that eliminate In from sides of the laser chips are employed.