Optical Beam Induced Current and Time Resolved Electro-Luminescence in Vertical Cavity Surface Emitting Lasers During Accelerated Aging

Adam W. Bushmaker,Brendan Foran,Zachary Lingley,Yongkun Sin,Miles Brodie

doi:10.1109/jphot.2019.2934945

Adam W. Bushmaker, Brendan Foran + Show 3 more

Open Access

https://doi.org/10.1109/jphot.2019.2934945

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Journal: IEEE Photonics Journal	Publication Date: Oct 1, 2019
Citations: 8	License type: CC BY 4.0

Affiliation: The Aerospace Corporation

Abstract

Vertical Cavity Surface Emitting Lasers are characterized under a high magnification optical microscope for reliability during accelerated aging using Optical Beam Induced Current and Electroluminescence imaging and spectroscopy, and also with electrical IV characterization. EL image data is captured with time resolution during device failure, and compared to the OBIC images, yielding insight into failure mechanisms. In particular, sudden, localized, permanent reductions in EL intensity around the outside of the laser oxide aperture are observed during the period of failure, indicating step-wise rather than gradual degradation in laser performance. These failure events are temporally correlated with sudden increases in low-injection junction current. Both OBIC and IV characterization suggest mid-gap defect formation as the cause of the observed failures.

Highlights

Vertical Cavity Surface Emitting Lasers (VCSELs) have been adopted rapidly in many fields, including remote sensing, illumination, laser excitation, and short-haul high data-rate fiber communications
It is possible that the observed signals come from Seebeck Effect Imaging (SEI) [13], [14], which are generated by temperature gradients in areas exhibiting the Seebeck effects, as in a thermocouple or thermoelectric semiconductor junction
We have presented before/after optical beam induced current (OBIC) images, time resolved EL images, and electrical IV curves from oxide VCSELs measured during accelerated life testing

Summary

Introduction

Vertical Cavity Surface Emitting Lasers (VCSELs) have been adopted rapidly in many fields, including remote sensing, illumination, laser excitation, and short-haul high data-rate fiber communications. This is due to a number of advantageous attributes offered by VCSEL technology, such as low cost, small size, high speed, and a native circular beam shape [1]–[4]. One of the most promising applications for VCSEL technology is high data-rate fiber communications, where VCSELs can send digital data at rates up to 56 Gb/s over short distances [5]. There are many possible failure modes in VCSELs, including semiconductor lattice defects such as the so-called “Dark-line” defects, dopant migration, non-uniform current injection, and copper poisoning [9]

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