Chapter 2
Principles and Characteristics of NIR
Spectroscopy
Yukihiro Ozaki and Yusuke Morisawa
Abstract This chapter describes the principles and characteristics of NIR spectroscopy. It is divided into two subchapters, 2–1. Characteristics and advantages of
NIR spectroscopy: In this subchapter some emphasis is put on the versatility of NIR
spectroscopy. Some examples of NIR spectra are explained 2–2. Principles of NIR
spectroscopy based on quantum mechanics: To understand principles of NIR spectroscopy, principles of IR spectroscopy are described using quantum mechanics first,
and then detailed explanation about molecular vibrations-fundamentals, overtones
and combinations is given. Anharmonicity is mentioned briefly.
Keywords Molecular vibrations · Vibrational spectroscopy · Overtones ·
Combinations · Anharmonicity
NIR spectroscopy has very unique characteristics and advantages in comparison with
other spectroscopy like ultraviolet-visible (UV-Vis), IR, and Raman spectroscopy.
Those characteristics and advantages of NIR spectroscopy all come from anharmonicity of vibrational modes. Hence, it is important to learn the characteristics and
advantages of NIR spectroscopy in relation with anharmonicity, whose description
needs fundamental knowledge of quantum mechanics.
Y. Ozaki (B)
School of Science and Technology, Kwansei Gakuin University, Sanda, Japan
e-mail: yukiz89016@gmail.com
Toyota Physical and Chemical Research Institute, Nagakute, Japan
Y. Morisawa
School of Science and Engineering, Kindai University, Higashiosaka, Japan
© Springer Nature Singapore Pte Ltd. 2021
Y. Ozaki et al. (eds.), Near-Infrared Spectroscopy,
https://doi.org/10.1007/978-981-15-8648-4_2
11
Principles and Characteristics of NIR
Spectroscopy
Yukihiro Ozaki and Yusuke Morisawa
Abstract This chapter describes the principles and characteristics of NIR spectroscopy. It is divided into two subchapters, 2–1. Characteristics and advantages of
NIR spectroscopy: In this subchapter some emphasis is put on the versatility of NIR
spectroscopy. Some examples of NIR spectra are explained 2–2. Principles of NIR
spectroscopy based on quantum mechanics: To understand principles of NIR spectroscopy, principles of IR spectroscopy are described using quantum mechanics first,
and then detailed explanation about molecular vibrations-fundamentals, overtones
and combinations is given. Anharmonicity is mentioned briefly.
Keywords Molecular vibrations · Vibrational spectroscopy · Overtones ·
Combinations · Anharmonicity
NIR spectroscopy has very unique characteristics and advantages in comparison with
other spectroscopy like ultraviolet-visible (UV-Vis), IR, and Raman spectroscopy.
Those characteristics and advantages of NIR spectroscopy all come from anharmonicity of vibrational modes. Hence, it is important to learn the characteristics and
advantages of NIR spectroscopy in relation with anharmonicity, whose description
needs fundamental knowledge of quantum mechanics.
Y. Ozaki (B)
School of Science and Technology, Kwansei Gakuin University, Sanda, Japan
e-mail: yukiz89016@gmail.com
Toyota Physical and Chemical Research Institute, Nagakute, Japan
Y. Morisawa
School of Science and Engineering, Kindai University, Higashiosaka, Japan
© Springer Nature Singapore Pte Ltd. 2021
Y. Ozaki et al. (eds.), Near-Infrared Spectroscopy,
https://doi.org/10.1007/978-981-15-8648-4_2
11