5-Picosecond Photoconductive Sampling Oscilloscope

We are proposing a fundamental leap forwards in both technique and performance of measurement techniques for characterizing ultrahigh-speed electronic signals. We will design and build a laser-based oscilloscope for characterizing electrical signals in the picosecond time regime. The oscilloscope will be based on the use of non-stoichiometrically grown InGaAs:As photoconductive detector elements that will function as ultrahigh-speed sampling gates when illuminated by infrared picosecond laser pulses. These detectors are the fastest in the world and represent the critical link that enables optical pulses to effictively be used to meaurte electrical signals. Our goals for this system are to obtain a temporal resolution of less than 5 picoseconds and a sensitivity of less than 100uV/Hz. Picosecond lasers have now become standard, off-the-shelf items. The use of infrared pulses is desirable because they can be generated by compact fiber pumed by highly efficient diode lasers. This combination of technologies will enable the development of a compact instrumentation system that will allow users to characterize picosecond electrical signals with unprecedented temporal resolution and accuracy. These laser-based sampling oscilloscopes will usher in a new era of jitter-free picosecond instrumentation that makes working in the picosecond regime natural.