Reliability of 980-nm laser diodes based on Novalux extended-cavity surface-emitting laser (NECSEL) concept

Abstract

The reliability of novel, electrically pumped, vertical cavity 980-nm InGaAs lasers is demonstrated through accelerated life testing (ALT). The ALT methodology is used to detect failure modes as well as to obtain failure statistics. The time-to-failure (TTF) distribution and acceleration model are determined from over 200 devices tested from multiple wafers and assembly lots to account for process variation. The failure mode observed was gradual power degradation, while all other laser diode characteristics, e.g., threshold current, operating current and wavelength, remained stable. Laser output power degraded linearly in t 1/2 , where t is the stress time. The acceleration model best fitting the data is Black's equation with thermal activation energy of 0.89 eV and current density coefficient of 2.9. Verification of the acceleration model was confirmed through life testing over 500 devices at field operating conditions. The high level of reliability demonstrated meets strict telecommunications requirements.

Diode Lasers for Displays

“…To achieve high efficiency, the substrate that is included in the resonator must have both low optical loss and low electrical resistance [2-6]. All of these issues have been overcome at the same time and present devices are produced on 4-inch GaAs wafers with reliability of more than one million hours mean time to failure [7].…”