Study of electric field distribution in GaAs materials and devices using electro-optic probing technique

摘要

[[abstract]]Continuous wave (CW) and pulse electro-optic probing techniques have been applied to study the electric field distribution in GaAs material and device. We have utilized the CW electro-optic probing to measure the electric field profile of a coplanar waveguide made on a GaAs semi-insulating substrate. This probing technique can be generalized to map out the three-dimensional field distribution. In addition, the inhomogeneous distribution of deep levels in a liquid encapsulated Czochralski (LEC) semi-insulating GaAs substrate is probed. The change of deep level concentration near the GaAs substrate surface after thermal annealing is in turn detected. Using the concept of harmonic mixing, we are able to employ the pulsed electro-optic probing to measure the standing wave pattern in a GaAs coplanar waveguide with various terminations. This technique is demonstrated at microwave frequencies up to 20.10 GHz. The measured effective indexes of refraction are in good agreement with those predicted by theory