Abstract: A method for modifying a surface by generating nanotubes at one or more selected sites on the surface, the surface including a first metal. The method includes the steps of positioning at least one cathode and at least one anode relative to the surface in an electrolyte solution including a fluoride salt of a second metal, and applying a voltage between the at least one anode and the at least one cathode sufficient to generate nanotubes at one or more selected sites on the surface and to inhibit nanotube formation at one or more of the other selected sites, wherein the nanotubes include the first metal and the second metal.

Abstract: A Raman analyzer for analyzing light emitted from a Raman cell is provided that has a beam splitter configured to split the light emitted from the Raman cell into a first beam and a second beam. An atomic vapor filter can be used to filter a Raman scattered line from the first beam and a chopper system can periodically interrupt the first and second beams that are directed towards a photo detector, which can convert light from the first and second beams into an electrical signal. The signal output from the photo detector can optionally be amplified, digitized, Fourier filtered, and/or subjected to Fourier analysis.