180-GHz Gain-Bandwidth Product Back-Side-Illuminated GaInAs–AlInAs APDs

This letter presents a comparative study of GaInAs-AlInAs avalanche photodiodes with different absorption layer thicknesses. Simulations concerning dark current and frequency response have been carried out to study the influence of the vertical structure on functional characteristics. Fabricated devices achieved gain-bandwidth product GtimesB as high as 180 GHz combined with very low dark current and low excess noise factor.