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.
An adjustable lens is disclosed for use in an optical profilometer system. The adjustable lens includes a plurality of elements that are mutually spaced from another in a first position and provides a first focal point for an incident electromagnetic field having a first frequency incident at a first angle with respect to the plurality of elements. The adjustable lens also includes an actuation unit for changing the focal point of the plurality of elements to provide a second focal point for the incident electromagnetic field having the first frequency incident at the first angle with respect to the plurality of elements.