Patent ID: 9229045
Filing Date: 2016-01-05
CPC Classification: G01R

Claim Text:
1. A method for in-situ characterization of a single solid-state light source, the method comprising, in at least one computer: identifying a current-voltage characteristic behavior of the single solid-state light source over a region of interest within a current-voltage relationship of the single solid-state light source, wherein the single solid-state light source is a vertical-cavity surface-emitting laser (VCSEL); monitoring a voltage and a current of the single solid-state light source during an in-situ operation of the single solid-state light source; characterizing the health of the single solid-state light source based on an analysis that involves a regression analysis that generates an estimate of a current-voltage relationship for the single solid-state light source based on a relationship of the monitored voltage and current, wherein characterizing the health of the single solid-state light source includes characterizing a likelihood of an impending failure of the single solid-state light source; generating an alarm when a result of a sequential hypothesis test of one or more residuals computed from the regression analysis indicate that the health of the single solid-state light source is degraded, wherein said generating the alarm involves determining a cause of degradation from a plurality of possible causes of degradation based on the relationship of the monitored voltage and current of the single solid-state light source during the in-situ operation of the single solid-state light source; and taking remedial action when the health of the single solid-state light source is degraded.