Optimization of multiple quantum well structures for waveguide electroabsorption modulators

A systematic approach for optimizing the performance of a multiple quantum well electroabsorption waveguide modulator is presented. The primary criterion of the modulator performance for digital and analog applications is taken to be the change of transmission Delta T at a given applied electric field. The design variables used to maximize Delta T include the device length (L), as well as the quantum well width and composition which determine the electroabsorption ( Delta alpha ) and the residual absorption ( alpha /sub 0/) at a given photon wavelength. Within the range of Delta T that can satisfy the system requirement, the L is then minimized to maximize the bandwidth. The effect of the guided wave index profile and the electrical properties of the p-i-n structure on the bandwidth and the drive voltage requirement is discussed.<
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