《FIGERPRINT DETECTION WITH LASERS》

1Light, Spectra, and Lasers1

1.1 Light3

1.2 Atoms, Molecules, and Spectra6

1.3 Molecular Spectra: A Closer Look9

1.4 Principles of Laser Operation14

1.5Types of Lasers15

References20

Additional Readings21

2Spectroscopic Instrumentation23

2.1 Monochromators24

2.2 Photomultiplier Tubes26

2.3 Detection Electronics28

2.4 Absorption Spectra31

2.5 Wavelength Response Calibration33

2.6 Emission Spectra34

2.7 Excitation Spectra38

2.8 Raman Spectra39

2.9 Luminescence Lifetime Measurement40

2.10Instruments42

References44

Additional Readings44

3Laser Detection of Latent Fingerprints45

3.1 Some Conventional Methods46

3.2Laser Detection of Latent Prints-Inherent Fingerprint Luminescence47

color plates 1-8 53-60

3.3 Laser Detection of Latent Prints-Treatment with Fluorescers62

3.4 Laser Detection of Latent Prints-Chemicals Reacting with Fingerprint Material to Form Luminescent Reaction Products65

3.5 Laser Detection of Latent Prints-Treatment with Phosphorescers68

3.6Case Applications71

References77

4Applications of Spectroscopy to Latent77

4 Fingerprint Detection79

4.1 Latent Fingerprint Luminescence79

4.2 Filters81

4.3 Nature of Luminescers in Fingerprint Material87

4.4 Detection of Weak Prints88

4.5Prospects for Lasers and Spectroscopy in Forensic Analysis93

References98

5Operation of Ar-Lasers99

5.1 Water Cooling100

5.2 Gas Pressure100

5.3 Cleaning of Optical Surfaces100

5.4 Laser Alignment101

5.5 Laser Safety103

Index105