Patent ID: 6781686
Filing Date: 2004-08-24
Classification: G01N

Abstract:
A surface specific optical diagnostic system, comprising:a) a first optical source for providing a first laser input directable to an area of a surface to be interrogated, said first laser input having a pulse having a duration of about 50-100 femtoseconds; b) a second optical source for providing a second laser input directable to the surface area to be interrogated, said second laser input having a second pulse having a duration of about 50-100 femtoseconds, said first and second laser inputs being alignable so that their surface areas of optical illumination overlap on said interrogated surface, said second optical source including an optical delay line for temporarily synchronizing said first and second laser inputs; c) an output wavelength discriminator for receiving reflections of said first and second laser inputs from said interrogated surface, said output wavelength discriminator being substantially non-transmissive at the frequencies of the first laser input and the second laser input, but being substantially transmissive at the sum-frequency of said first laser input and said second laser input; d) imaging optics for receiving an output of said wavelength discriminator and directing the propagation of the output so that a real image is formed after propagation through said imaging optics; and, e) a position sensitive detector for monitoring the intensity of said real image at said sum-frequency so that the sum-frequency, as a function of surface position, is converted to an electronic signal equivalent to said real image, wherein utilization of the femtosecond duration laser inputs generates enhanced peak optical powers on the interrogated surface, producing an optimized sum-frequency reflection, resulting in minimized interrogation times.