Skip to Main Content
Your organization might have access to this article on the publisher's site. To check, click on this link:http://dx.doi.org/+10.1063/1.1145583
The electric field dependence of the absorption coefficient in semi‐insulating GaAs at the absorption edge was measured in a high‐voltage pulsed experiment. Pulse duration was kept below 50 ns in order to avoid thermal effects. A GaAs laser diode was used as a probe light source with wavelength varied from 902 to 911 nm. For fields up to 40 kV/cm the absorption coefficient increased from 3 to 17 cm-1 at 902 nm, with smaller absolute increases evident at the longer wavelengths. Calculation from theory was consistent with this behavior. The spatial variation of the electric field was also recorded with a CCD camera. This method was used as a diagnostic technique to study the field distribution during the switching cycle of a high‐power photoconductive switch. The described system could be used as a simple electric field probe with temporal resolution of 100 ps, or as a field mapping system with spatial resolution approaching 1 μm. © 1995 American Institute of Physics.