Premium
Fluorescence Spectra and Images of Latent Fingerprints Excited with a Tunable Laser in the Ultraviolet Region
Author(s) -
Akiba Norimitsu,
Saitoh Naoki,
Kuroki Kenro
Publication year - 2007
Publication title -
journal of forensic sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.715
H-Index - 96
eISSN - 1556-4029
pISSN - 0022-1198
DOI - 10.1111/j.1556-4029.2007.00532.x
Subject(s) - ultraviolet , fluorescence , laser , wavelength , excitation , nanosecond , excited state , excitation wavelength , spectral line , materials science , analytical chemistry (journal) , laser induced fluorescence , optical parametric oscillator , crystal (programming language) , optics , chemistry , optoelectronics , atomic physics , physics , quantum mechanics , chromatography , programming language , astronomy , computer science
Fluorescence spectra of sebum‐rich latent fingerprints were studied with a tunable laser for non‐destructive fingerprint detection without chemical treatment. The tunable laser consists of a nanosecond pulsed Nd‐YAG laser and an optical parametric oscillator (OPO) crystal. The fluorescence spectra and images were measured at various excitation wavelengths in the ultraviolet region by the time‐resolved fluorescence method. We have previously reported that a typical fluorescence spectrum of fingerprints consists of two peaks located at c. 330 and 440 nm. In order to determine the wavelength of optimal excitation, excitation spectra were measured at wavelengths ranging from 220 to 310 nm. The fluorescence intensity of the 330 nm peak became maximal with excitation at 280 nm. The images of latent fingerprints on white papers were also measured and the clearest image was obtained with excitation at 280 nm. The influence of continuous irradiation on the fluorescence of fingerprints was measured at the optimal excitation wavelengths. The 330 nm peak was strong at first and decreased with continuous irradiation, whereas the 440 nm peak, which was weak at first, increased gradually.