Design the Impact of Temperature on the Modulation Bandwidth of InGaAs vertical cavity surface emitting lasers (VCSELs) for Efficient Optical Interconnect

This simulation work, based on the design of an 850 nm ingaas/algaas quantum well (qws) vertical cavity surface emitting laser (vcsel), presents significant challenges, particularly due to the limitations of device bandwidth at higher temperatures. we propose a comprehensive modelling approach to optimize the dynamic performance of a vcsel structure with an oxide aperture diameter of 6 µm, specifically to achieve higher bandwidth at lower bias currents. the matlab simulation evaluates the variation of critical parameters, such as threshold current, differential efficiency, output power, and small-signal modulation, across a wide operating temperature range. our findings indicate that in static analysis, the threshold current exhibits a positive temperature dependence, increasing with rising temperature, while both differential efficiency and optical output power decrease. dynamic analysis reveals that although the 3-db modulation bandwidth reduces with temperature, the vcsel maintains high-speed performance exceeding 36 ghz at 20 °c and 24 ghz at 120 °c under a bias current of 14 ma. the temperature dependence of the modulation current efficiency factor (mcef) provides insight into optimizing vcsel structures for reliable high-speed operation over broad thermal conditions.