Monday, September 1, 2014

Electron microscope image capture with an oscilloscope

I show how I collect digital electron microscope images with my Tek MDO3000 oscilloscope.


  1. Hi Ben,

    Interesting video as always. Never really thought of using oscilloscope to capture images.

  2. Max, what you describe is actually how the SEM works. In order to simplify the process, I described pixels in my video, but in reality, the electron beam is constantly moving. The system is completely analog, so values are accumulated as the beam is in motion. If it moves more slowly, there will be a higher number of measurements per unit length, but there aren't any pixels or dwell spots in the beam's path.

    The electron signal from the sample is a lot like a 1-bit stream. The secondary electron detector doesn't measure the energy of each electron -- just the total number collected. This means that it is a sort of very low-level digital signal of sorts. The pulses from each electron are sent through a low-pass filter which converts them into an analog value that corresponds with the number of electrons per second. With modern high-speed digital circuitry it might be possible to count electrons one-by-one, but I'm not sure this would be better than filtering and measuring.

  3. Hi, I hope you read this, I'm trying to do the same thing but I can't "translate" the CSV file to an image, I do not have experience with Octave but I wish you could share your Script. Thanks

    1. Take a look at the links in the description here: