Submicron external electro-optic measuring system based on an electro-optic solid immersion lens

In this paper, an electro-optic solid immersion lens (EOSIL) is introduced, which is made of GaAs. A reflecting external electro-optic measuring syste m based on the EOS[L is built. With a hemispherical GaAs EOSIL used as the external probe, 0.7 mum spot size is obtained when the wavelength of the pr obing beast from a laser diode is 1.3 mum and a microscope objective with 0 .3 numerical aperture is used. The principle of the measuring system is ana lyzed by Jones matrix. By using the system, the electrical signals propagat ing on a microstrip transmission line are successfully measured. The voltag e sensitivity about 5 mV/root Hz is measured when 10kHz sinusoidal electric signal is applied on the microstrip line.