The potential of optical near-field photocurrent spectroscopy for analyzing microscopic aging processes in optoelectronic devices is demonstrated. The technique combines the subwavelength spatial resolution of near-field optics with tunable laser excitation, allowing for selective investigation of specific parts of the device structure. Experiments on GaAs/(AlGa)As high power laser diodes before and after accelerated aging provide direct visualization of defect growth within the p-i-n junction and information on aging-enhanced recombination processes close to the laser facet. The effect of wave guiding of the exciting light on the image formation is discussed. The nondestructiveness makes this technique a particularly attractive method for in situ analysis in high power laser diodes.
No takes yet. Share an insight, caveat, or question.
Richter et al. (1996) studied this question.