Patent ID: 7787118
Filing Date: 2010-08-31
Classification: G01N

Abstract:
1. A method of obtaining spectral information comprising: using a first excitation beam at a first excitation frequency and a second excitation beam at a second, different excitation frequency to initiate at least a first excitation and a second excitation in a surface—enhanced sample; using a third excitation beam at a third excitation frequency to initiate a third excitation; varying the excitation frequency of one of the first and second excitation beams; detecting an output signal having an output signal frequency that is different to each of said first, second an third excitation frequencies; identifying an output signal peak; and correlating the output signal peak with the first and second excitation frequencies to obtain spectral information on the sample; in which the surface enhanced sample substrate is configured to enhance the field corresponding to at least one of the first, second and third excitation beams, or to enhance an output field initiated in the sample.