摘要 |
A method for authenticating security markers includes illuminating the security marker with a laser, detecting an optical response from the security marker, changing a temperature of the laser to vary the wavelength of radiation produced by the laser; detecting changes in the optical response from the security marker as the wavelength of the radiation changes, comparing the optical response profile from the security marker as it varies with changes in wavelength to a reference profile; and authenticating the security marker if the optical response profile matches the reference profile. |