Abstract
Non-contact picosecond electro-optic sampling with a semiconductor laser is proposed and experimentally studied focusing on the practical application in the field of IC testing. Adoption of a laser diode pulse generator being compact, inexpensive, highly reliable and easy to electrically control makes possible the measurement without chopping of the electrical signals under test, and the measurement where strobe laser pulses are electrically synchronized to the clock signal.
A newly developed longitudinal E-O sampling probe having a transparent back-side electrode enables one to measure voltages independently on the shape and the direction of electrodes under test, and to exactly monitor the measuring point on the electrode. It also makes possible the absolute voltage measurement.
Reduction of noise of the optical receiver and the strobe pulses is experimentally investigated. In addition, the space dependent sensitivity is studied and greatly improved by adopting a new method.
The equivalent input noise of 75 mV/√Hz with a temporal resolution of 32 ps at the space of 20μm between the probe tip and the device under test has been demonstrated.
