One-shot single-emitter-resolved polarization and LIV+λ characterization of a VCSEL array at tempered conditions

To determine electro-optical characterization of laser diodes, various measurements are usually performed including LIV+λ (with spectrum) characterization. For VCSEL arrays with the existing solutions, it is hardly possible and timely expensive to perform these measurements since there are few up to some hundreds of single emitters within the array. VCSEL arrays are beneficial for technologies like structured light and Face ID, in which detailed characterization of individual emitters are required. Furthermore, polarized VCSEL arrays are unique and have potential applications, which then requires not only the LIV+λ but also polarization measurement of each emitter. Therefore, in this study, not only we extended the LIV+λ measurements to each individual emitters in a VCSEL array but also their polarization is measured. Our experimental design consists of a camera based radiant power and polarization measurement coupled to an array spectrometer. The system measures the absolute optical power, traceable to the standards. The VCSEL array mounted on a tempering system with a direct feedback loop. In order to characterize the stability of the VCSEL array in various environmental conditions, all the measurements were done further at multiple temperatures. Depending for which application the VCSEL will be, the valid range of the measured parameters of each emitter can be set. Therefore, non-functional emitters were determined. The design offers fast one-shot and comprehensive characterization of emitters of VCSEL arrays, allowing parallelization of the measurements to reduce overall measurement time and to determine damaged or out of spec VCSELs at early stage of the manufacturing process.