Electrical parasitics and parameter extraction of photonic crystal vertical-cavity surface-emitting lasers

Directly modulated vertical-cavity surface-emitting lasers (VCSELs) are the dominant digital light source in short-haul data communication links. To address the ever-increasing demand for improved performance, namely the power consumption, data rate, and device reliability, single mode proton-implanted photonic crystal vertical-cavity surface-emitting lasers have been designed and fabricated for high power and high speed operation. To characterize performance of these devices, we perform DC and small signal modulation analysis. Impedance characteristics and electrical parasitics are studied for various photonic crystal designs to understand factors which limit high speed modulation. Photonic crystal designs are found to have low differential resistance, but high parasitic capacitance. By including a diffusion capacitance term in the modulation response equation, scattering parameter fitting suggests the diffusion capacitance to be the limiting factor of intensity modulation. Extracted parameters from DC, impedance, and modulation response measurements are cross-checked to verify accuracy