Strain-balanced InGaP/InGaP multiple quantum well electroabsorption modulators on GaP and GaAsP.

摘要

his thesis reports on the results of work done on the use of the InGaP material system in strain-balanced MQW electroabsorption modulator structures operating near the minimum loss points of plastic optical fibers. Results are presented for both transmission and reflection mode structures grown by gas-source molecular beam epitaxy on graded buffer layers on GaP substrates and lattice matched buffers on ternary GaAsP substrates.;PIN MQW modulator structures were used to characterize the absorption modulation capabilities of InGaP/InGaP strain-balanced MQWs on both GaP and GaAsP substrates. Both the luminescence and absorption characteristics of the films near crossover were studied and PL was found to be significantly more sensitive to the indirect transition than was absorption strength, as expected.;Transmission modulators with differential transmission ;Reflection mode MQW modulators were fabricated on GaAsP substrates to demonstrate the improved performance of the absorption modulation of psuedomorphic devices over those grown on strain-relaxed buffers. Contrast ratio (CR) values ranging from 0.2 to 4.3 were measured for non-resonant and resonant devices, respectively, with corresponding reflectance difference