Optoelectronically generated transient radiation for broadband microwave measurements

The authors report the application of picosecond photoconductivity to broadband microwave measurements with optoelectronically generated, freely propagating, transient radiation. Based on integrated antennas to launch and receive electromagnetic pulses, this quasi-optical technique is useful for characterizing the complex dielectric constants of materials over a wide frequency range in a single measurement. The measured electric-field absorption coefficient and refractive index of fused silica are shown as an example. The results are consistent with previous data.