Patent ID: 9170203
Filing Date: 2015-10-27
Classification: G01J,G01N

Abstract:
1. A method for enhancing intensity of Raman emissions produced by excitation of a sample with a laser beam from a laser source, the laser source comprising a lens configured to focus the laser beam to a focal point a first distance from the lens, the laser beam comprising at least one wavelength and having a substantially conical dispersion from the focal point to a distance greater than the first distance, the conical dispersion defining a plurality of diameters increasing in size in a direction away from the focal point, and the method comprising: placing a microsphere between the radiation source and the sample at a second distance from the lens, the second distance being greater than the first distance, wherein the microsphere comprises a portion for receiving the laser beam and outputting a photonic nanojet to impinge on the sample, and the microsphere has a diameter and a refractive index; adjusting the second distance in relation to the first distance so that the diameter of the laser beam at the second distance is substantially the same as the diameter of the microsphere, wherein the diameter and refractive index of the microsphere and wavelength of the laser are effective to confine the laser beam in the photonic nanojet by an amount sufficient to enhance the Raman emissions by a factor of at least about 15; and directing the laser beam at the microsphere to impinge the laser beam on the microsphere and output the photonic nanojet to impinge on the sample, excite the sample, and produce the Raman emissions.