物质的红外吸收光谱有时被称为分子指纹。 尽管经常用于识别材料，但红外光谱也可用于量化吸收分子的数量。 吸收光谱，荧光光谱，拉曼光谱和表面增强拉曼光谱通常使用激光作为能源。 激光光谱学提供有关相干光与物质相互作用的信息。 激光光谱通常具有高分辨率和灵敏度。 质谱仪源产生离子。 关于样品的信息可以通过分析离子在与样品相互作用时的分散来获得，通常使用质荷比。 在这种类型的光谱学中，记录的每个光学波长用包含原始波长信息的音频编码。 然后波长分析仪可以重建原始光谱。
澳洲詹姆斯库克大学Essay代写：光谱学简介
The infrared absorption spectrum of a substance is sometimes called its molecular fingerprint. Although frequently used to identify materials, infrared spectroscopy also may be used to quantify the number of absorbing molecules. Absorption spectroscopy, fluorescence spectroscopy, Raman spectroscopy, and surface-enhanced Raman spectroscopy commonly use laser light as an energy source. Laser spectroscopies provide information about the interaction of coherent light with matter. Laser spectroscopy generally has high resolution and sensitivity. A mass spectrometer source produces ions. Information about a sample may be obtained by analyzing the dispersion of ions when they interact with the sample, generally using the mass-to-charge ratio. In this type of spectroscopy, each optical wavelength that is recorded is encoded with an audio frequency containing the original wavelength information. A wavelength analyzer can then reconstruct the original spectrum.