High resolution non-contact interior profilometer

The present invention generally relates to procedures for inspecting the condition of manufactured articles, and, more particularly to the inspection of the interiors of manufactured articles such as tanks, medical implants, turbines, and other closed applications in which only limited access is provided. This invention was made with Government support under Contract No. W-7405-ENG-36 awarded by the U.S. Department of Energy. The Government has certain rights in the invention. Apparatus and method for inspecting the interior surfaces of devices such as vessels having a single entry port. Laser energy is introduced into a device under test and to a time delay. Light reflected from the interior surfaces of the device under test is introduced into one end of a dye-cell and the time-delayed light is introduced into the other end. The amount of time delay is adjusted to produce two-photon fluorescence in the dye-cell so that the amount of time delay is representative of the interior surfaces of the device under test.