光譜學/sp?k?tr?sk?pi /是對物質與電磁輻射之間相互作用的研究。從歷史上看，光譜學是通過棱鏡研究可見光的波長分布而產生的。后來，這個概念得到了很大的擴展，包括與輻射能量的任何相互作用，作為其波長或頻率的函數，主要是在電磁頻譜中，雖然物質波和聲波也可以被認為是輻射能量的形式；近年來，在LIGO和激光干涉測量的背景下，連引力波都很難與光譜特征聯系起來。光譜數據通常用發射光譜來表示，發射光譜是感興趣的響應隨波長或頻率變化的曲線。光譜學，主要是在電磁光譜中，是物理學、化學和天文學領域的基本探索工具，允許在原子尺度、分子尺度、宏觀尺度和天文距離上研究物質的組成、物理結構和電子結構。生物醫學光譜學在組織分析和醫學成像領域的重要應用。

Spectroscopy /sp?k?tr?sk?pi/ is the study of the interaction between matter and electromagnetic radiation.Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, by a prism. Later the concept was expanded greatly to include any interaction with radiative energy as a function of its wavelength or frequency, predominantly in the electromagnetic spectrum, though matter waves and acoustic waves can also be considered forms of radiative energy; recently, with tremendous difficulty, even gravitational waves have been associated with a spectral signature in the context of LIGO and laser interferometry. Spectroscopic data are often represented by an emission spectrum, a plot of the response of interest as a function of wavelength or frequency.Spectroscopy, primarily in the electromagnetic spectrum, is a fundamental exploratory tool in the fields of physics, chemistry, and astronomy, allowing the composition, physical structure and electronic structure of matter to be investigated at atomic scale, molecular scale, macro scale, and over astronomical distances. Important applications arise from biomedical spectroscopy in the areas of tissue analysis and medical imaging.