Design of Low ${V}_{\pi}$ High-Speed GaAs Travelling-Wave Electrooptic Phase Modulators Using an n-i-p-n Structure

GaAs-based electrooptic phase modulators using an n-i-p-n structure and coplanar waveguide traveling-wave electrodes are designed using the compact 2-D finite-difference time-domain technique and Pade approximation transform. By optimization, an electrical 3-dB bandwidth of 40 GHz and a 6.6-V
V

_pi
are predicted for a 5-mm-long modulator.