Analysis and design of high-speed high-efficiency GaAs-AlGaAs double-heterostructure waveguide phase modulator

A P-p-i-n-N, GaAs-AlGaAs, TE/TM mode phase modulator, which has both the high phase shift efficiency of a p-n homojunction modulator and the high speed associated with a P-i-N modulator, is considered by incorporating p- and n-GaAs buffer layers and utilizing the higher order effects in these layers. The device structure is analyzed by considering the individual contributions of both the electrooptic (linear electrooptic (LEO) and quadratic electrooptic (QEO)) effects and the free carrier (plasma (PL) and bandgap shift (BS)) effects. These effects are studied in detail as a function of the reverse bias, operating wavelength, doping concentration, and intrinsic layer thickness. The results are in excellent agreement with the theoretical predictions.<
>