Research On With Ultraviolet Laser Fingerprint Identification System

Now with the increasing of the crime rate, how to identify the suspect's personal information effectively becomes the primary concern of the relevant departments. Personal fingerprints, which are different among human beings are the most effective signs, so the detection of fingerprints is on a very important status.By using 266 nm short-wave ultraviolet laser, long-wave ultraviolet fluorescence can be excited and so that the latent fingerprints can be detected. The short-wave ultraviolet laser is provided by the 266 nm Nd: YAG laser. BBO crystal is selected as the four times harmonic components of the laser. The output laser is irradiated on a paper with the fingerprint sample. The fluorescence excited from fingerprint is received by high-sensitivity CCD camera, and then we can find the position of the fingerprint. We record the inherent fluorescence from fingerprint with ultraviolet luminescence photograph. The detection efficiency with this method is high up to 67 %,which is 3%～22% higher than with other visible fluorescence, such as Argon ion laser.