Zero chirp asymmetric Fabry-Perot electroabsorption modulator using coupled quantum wells

A zero-chirp asymmetric Fabry-Perot reflection InGaAs QW modulator is created by placing coupled quantum wells in the intrinsic region of a reverse-biased p-i-n diode asymmetric Fabry-Perot cavity. Unlike single quantum wells which necessarily produce chirping during the switching cycle, these coupled quantum wells provide large absorption changes with zero refractive index changes over the entire voltage swing; the resultant cavity structure shows reflectivity changes with zero experimental phase change over the same voltage range. The tradeoff in reflectivity change required in order to obtain zero chirp is described. This tradeoff is a result of the different switching mechanisms used in coupled quantum wells versus single quantum wells.