Picosecond dynamics of optical gain switching in vertical cavity emitting lasers

It is demonstrated that optically gain switched GaAs vertical lasers (VSELs) with short cavity lengths can generate pulses as short as 4 ps, with delays as short as 20 ps. A model of the large-signal response of VSELs to short optical input pulses is presented. The results demonstrate that the critical parameter of determining VSEL response time is the cavity length. A numerical solution to the rate equations is used to calculate the output pulsewidth and delay, given a specific cavity design and set of input conditions. Calculated results are compared to experimental data. Output pulse dependencies on input pulsewidth and power are examined for different cavity designs. The results of the calculations are used to generate design curves for future devices.<
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