High-speed, high-impedance external photoconductive-type sampling probe/pulser

A probe system for achieving high frequency electrical communication with a device under test, the probe system comprising:

• probe tip means for contacting electrically the device under test, said probe tip means having a tip radius of less than 1 .mu.m;
• terminal means for communicating electrically with said probe tip means;
• and
• photoresponsive gate means formed of submicron gate elements, said photoresponsive gate means being interposed between said probe tip means and said terminal means for controlling electrical conduction between said probe tip means and said terminal means in response to an optical signal, said photoresponsive gate means being formed of a plurality of interdigitated gate electrode elements arranged approximately between 1 .mu.m and 2 .mu.m of one another.

A pulser/sampler probe system for delivering an electrical pulse having high frequency energy content to a device under test and receiving electrical energy from the device under test, the pulser/sampler probe system comprising:

• probe tip means for contacting electrically the device under test, said probe tip means having a submicron tip radius;
• probe tip electrode means for communicating electrically with said probe tip means;
• input electrode means for receiving an input electrical signal;
• input photoresponsive gate means formed of submicron gate elements and interposed between said probe tip electrode means and said input electrode means for controlling electrical conduction therebetween in response to a first optical signal;
• output electrode means for receiving an output electrical signal from said probe tip electrode means;
• and
• output photoresponsive gate means formed of submicron gate elements and interposed between said probe tip electrode means and said output electrode means for controlling electrical conduction therebetween in response to a second optical signal.