1 Light, Spectra, and Lasers 1
1.1 Light 3
1.2 Atoms, Molecules, and Spectra 6
1.3 Molecular Spectra: A Closer Look 9
1.4 Principles of Laser Operation 14
1.5 Types of Lasers 15
References 20
Additional Readings 21
2 Spectroscopic Instrumentation 23
2.1 Monochromators 24
2.2 Photomultiplier Tubes 26
2.3 Detection Electronics 28
2.4 Absorption Spectra 31
2.5 Wavelength Response Calibration 33
2.6 Emission Spectra 34
2.7 Excitation Spectra 38
2.8 Raman Spectra 39
2.9 Luminescence Lifetime Measurement 40
2.10 Instruments 42
References 44
Additional Readings 44
3 Laser Detection of Latent Fingerprints 45
3.1 Some Conventional Methods 46
3.2 Laser Detection of Latent Prints-Inherent Fingerprint Luminescence 47
color plates 1-8 53- 60
3.3 Laser Detection of Latent Prints-Treatment with Fluorescers 62
3.4 Laser Detection of Latent Prints-Chemicals Reacting with Fingerprint Material to Form Luminescent Reaction Products 65
3.5 Laser Detection of Latent Prints-Treatment with Phosphorescers 68
3.6 Case Applications 71
References 77
4 Applications of Spectroscopy to Latent 77
4 Fingerprint Detection 79
4.1 Latent Fingerprint Luminescence 79
4.2 Filters 81
4.3 Nature of Luminescers in Fingerprint Material 87
4.4 Detection of Weak Prints 88
4.5 Prospects for Lasers and Spectroscopy in Forensic Analysis 93
References 98
5 Operation of Ar-Lasers 99
5.1 Water Cooling 100
5.2 Gas Pressure 100
5.3 Cleaning of Optical Surfaces 100
5.4 Laser Alignment 101
5.5 Laser Safety 103
Index 105