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ABSTRACT:
The advent of laser technology in the society has created a boon in the field of forensic science. Various laser sources have been used in the field of forensics to facilitate their use in solving crimes. Laser is a device that produces and amplifies a narrow beam of coherent light by making use of the processes that amplify blight signals which are being generated by some other means. The basic principle of laser amplification is stimulated emission and Brian. E. Dalrymple is known for introduction of laser for its utilization in the forensic field. The Laser was used for the first time as forensic light source for the identification of fingerprints and other evidence detection such as elemental analysis of glass and paints, characterisation of gunshot residue, crime scene investigation, detection of biological evidences, traces of explosives, analysis of soils and sediments, stress and fatigue in metals. The article emphasis on the use of laser in the forensic field which will prove beneficial in accurate and speedy analysis of the cases.
KEYWORDS: Laser, Monochromatic, Optical cavity, LA-ICPMS, fluorescamine, Ablation cell.
INTRODUCTION:
A laser is a device that emits light through a process called as optical magnification based on Stimulated emission of photons [1]It is a type of light source which has certain specific properties that makes it a special light .The word LASER stands for :-
L- Light
A-Amplification by the
S-Stimulated
E-Emission of
R-Radiation [2]
Albert Einstein in 1917 postulated the Stimulated emission theory which makes the process of laser possible.[3]According to him the population inversion exists between upper and lower levels among atomic systems which helps in the realization of amplified stimulated emission which has the same frequency and phase as the incident radiation.[4]However, it was in late 1940s and fifties that scientists and engineers did extensive work to realize a practical device based on the principle of stimulated emission. Notable scientists who pioneered the work include Charles Townes, Joseph Weber, Prokhorov and Nikolai G Basov.[3][4]
Brian E. Dalrymple is an Ontarian fingerprint scientist known for introducing for the first time the use of lasers (with colleague Duff and Menzel) as a forensic light sources for fingerprints and other evidence detection, using the Argon Ion Lasers to detect the inherent fluorescence...