We investigated the low-frequency optical and electrical noise characteristics and their cross-correlation factor of the 808 nm laser diodes (LDs) samples, whose performances were degraded and stabilized after operating a period of time or during ex-factory reliability lifetime tests. It was shown that the optical noise in unreliable samples exhibited white components in the frequency range from 1 kHz to 10 kHz, while a Lorentzian-type component was superimposed on 1 / f electrical noise. Meanwhile, the optical and electrical noise correlation exhibited positive result. In contrast, both low-frequency optical and electrical noise presented pure 1 / f -type fluctuations in stable samples. These presented results suggest that it is feasible to employ low-frequency noise measurements as a tool for predicting and diagnosing the reliability of LDs.

We present a 1 / f noise model of 980 nm InGaAs/GaAs laser diodes (LDs) operated below the lasing threshold to study the correlation between 1 / f noise and fluctuation of surface nonradiative recombination current I n r . In InGaAs/GaAs LDs, nonradiative recombination current components have been identified as being primarily related to surface recombination, which depends on surface oxide traps and lattice dislocation. An analysis of the experimental comparison of I n r and 1 / f noise spectral density with constant current and temperature aging tests further shows the correlation and verifies the 1 / f noise model, which can be interpreted as a change in carriers and trap density of a certain surface. This model permits facet stability to be investigated.

No abstract