Two-dimensional direct electra-optic field mapping in a monolithic integrated GaAs amplifier

For the first time experimental results of two-dimensional electric field mapping within a GaAs-MMIC using the direct electro-optic probing technique are presented. As an example, maps of different sections of a coplanar 1-12 GHz travelling-wave amplifier such as a thin film resistor, a MESFET, the drain transmlssion line, and an air-bridge are displayed showing characteristic field distributions in a MMIC amplifier at different driving frequencies. Evaluating the results, signal levels at internal points of the circuit can be studied providing quantitative informations about circuit-internal transmission characteristics such as attenuation or amplification of the microwave signal.