The aberration corrected microscope PEEM-3 employs a curved electron mirror to counter the lowest order aberrations of the electron lenses and the accelerating field.

Using a dense relativistic electron mirror created from a high-intensity laser pulse and nanometre-scale foil, the frequency of the laser pulse was shown to shift coherently from infrared to the ultraviolet.

In the experiment, the incredibly high velocity of the electron mirror gave rise to a change in frequency upon reflection from the near infrared to the extreme ultraviolet up to a wavelength of 60 to 80 nanometre.