Transmission
Electron Microscope(y). TEM comes in handy when we want to check out things with smaller resolution than that offered by a regular (light) microscope. While a
light microscope typically uses a series of glass lenses to focus the light it uses for measurement, TEM uses either
electrostatic lenses or
electromagnetic lenses to focus a beam of energized electrons. The shorter
wavelength of the
electron beam gives us the better resolution – in theory the best resolution for a light microscope should be something like 155
nm, while the best resolution for an electron microscope should be something smaller than 0.02
A.
While people nowdays often associate TEM with Medicine or biology it's also used in material research and electronics.