ELECTROOPTICAL SAMPLING PROBER

摘要

PROBLEM TO BE SOLVED: To provide an electrooptical sampling prober that is capable of accurate measurement constantly by adjusting the quantity of light entering an electroptical sampling optical system. SOLUTION: The electrooptical sampling prober is provided with an electrooptical element 2 that is in contact with wiring on the surface of an IC wafer 1 to be measured where an electric field is applied via the wiring and optical characteristics change and an electrooptical sampling optical system module 6a that has a polarization beam splitter, a wavelength plate, and a photodiode inside while a laser beam being emitted from the outside is transmitted in the electrooptical element and light being reflected on the surface of the electrooptical element that opposes wiring is separated and converted to an electrical signal. The electrooptical sampling prober is provided with an incidence quantity-of-light adjustment part 5 for adjusting the quantity of light where the laser beam being emitted from the outside enters the electrooptical sampling optical system module 6a on the light source side for emitting the laser beam from the electrooptical sampling optical system module 6a.