Wide temperature operational range of a 1310 nm AlGaInAs MQW-DFB laser with silicon oxynitride as a facet coating

We successfully fabricated 1310 nm AlGaInAs MQW–DFB laser diodes with silicon oxynitride (SiON) as an AR facet coating. In this report, the low reflectivity of the single layer SiON film on the facet of the 1310 nm DFB LD is achieved, with the result that the FP mode can be effectively suppressed over a wide temperature range. The AlGaInAs MQWs is also adopted in order to achieve a good temperature performance of the 1310 nm DFB LD. We demonstrate that these devices have high slope efficiency, low threshold current, and high SMSR characteristics over the temperature range of −40 °C to 95 °C. Less than 1 dB degradation of slope efficiency was obtained when the temperature increased from 25 °C up to 95 °C. The side mode suppression ratio (SMSR) above 37 dB and clear openings of eye diagrams at 2.5 G modulation were maintained within the temperature range of −40 °C to 95 °C. These superior characteristics over the very wide temperature range of 1310 nm DFB laser diodes were achieved by the combination of AlGaInAs MQW and silicon oxynitride AR coating deposited on the facet.