Empirical Modeling and measurement of the Pulsed Junction Temperature of VCSEL

Abstract

An IR vertical-cavity surface-emitting laser (VCSEL) with a peak wavelength 940nm for ToF/Flood applications is characterized by the empirical modelling. This paper presents a novel approach to predict pulsed junction temperature rise of VCSELs using T3ster to extend the time-resolved measuring with a constant bias current based on the JESD51-14. For different DC bias currents, it is found the normalized junction temperature rise and drop curves with a reflectional symmetry suggest the same thermal model for simplifying the measurement. For the pulse bias, the thermal behavior of VCSEL due to frequency, duty and pulse number is studied. And an algorithm predicting the pulsed junction temperature rise and fluctuation were proposed and showing a good consistent result with the measurement of the T3ster at the first few pulses with low duties. The result also shown the pulsed optical power output was reduced due to the increase of the junction temperature rise in the pulse duty.