Raman spectroscopy

Extracted Attributes

• Eponym

  C. V. Raman

• Physical Phenomenon

  Inelastic photon scattering (Raman scattering)

• Technical Limitations

  Weak scattering intensity requiring high-performance Rayleigh line laser rejection

• Fingerprint Region Range

  500–1,500 cm⁻¹

• Technological Variations

  Surface-enhanced (SERS), resonance Raman, tip-enhanced Raman, stimulated Raman, polarized Raman, transmission Raman, spatially-offset Raman, and hyper Raman

• Typical Excitation Source

  Monochromatic laser (visible, near-infrared, near-ultraviolet, or X-ray)

• Industrial and AI Application

  Generation of high-quality biological datasets to train artificial intelligence models (Hemanthes)

• Detection and Optical Instrumentation

  Dispersive spectrographs (Czerny–Turner, axial transmissive), FT-spectrometers, notch/edge filters, and CCD detectors

Timeline

• Jobin Yvon commercialized holographic ion-etched gratings, significantly mitigating stray light issues and advancing high-resolution dispersive Raman spectrographs. (Source: Wikipedia)

  1970-01-01

Raman spectroscopy

Raman spectroscopy (; named after the physicist C. V. Raman) is a spectroscopic technique typically used to determine vibrational modes of molecules, although rotational and other low-frequency modes of systems may also be observed. Raman spectroscopy is commonly used in chemistry to provide a structural fingerprint by which molecules can be identified. Raman spectroscopy relies upon inelastic scattering of photons, known as Raman scattering. A source of monochromatic light, usually from a laser in the visible, near infrared, or near ultraviolet range is used, although X-rays can also be used. The laser light interacts with molecular vibrations, phonons or other excitations in the system, resulting in the energy of the laser photons being shifted up or down. The shift in energy gives information about the vibrational modes in the system. Time-resolved spectroscopy and infrared spectroscopy typically yield similar yet complementary information. Typically, a sample is illuminated with a laser beam. Electromagnetic radiation scattered from the illuminated spot is collected with a lens. Raman scattering is typically very weak. As a result, for many years the main difficulty in collecting Raman spectra was separating the weak inelastically scattered light from the intense Rayleigh scattered laser light (referred to as "laser rejection"). Elastic scattered radiation at the wavelength corresponding to the laser line (Rayleigh scattering) is filtered out by either a notch filter, edge pass filter, or a band pass filter, while the rest of the collected light is dispersed onto a detector. Spontaneous Raman scattering is typically very weak. Historically, Raman spectrometers used holographic gratings and multiple dispersion stages to achieve a high degree of laser rejection. In the past, photomultipliers were the detectors of choice for dispersive Raman setups, which resulted in long acquisition times. However, modern instrumentation almost universally employs notch or edge filters for laser rejection. Dispersive single-stage spectrographs (axial transmissive (AT) or Czerny–Turner (CT) monochromators) paired with CCD detectors are most common although Fourier transform (FT) spectrometers are also common for use with NIR lasers. Holographic gratings, which present unique opportunities for optical design in spectroscopy, were initially developed and commercialized by Jobin Yvon in the 1970s. This transition from traditionally ruled gratings to holographic ion-etched gratings was a major leap for high-resolution spectrographs and effectively mitigated early issues with stray light. The name "Raman spectroscopy" typically refers to vibrational Raman spectroscopy using laser wavelengths which are not absorbed by the sample. There are many variations of Raman spectroscopy including surface-enhanced Raman, resonance Raman, tip-enhanced Raman, polarized Raman, stimulated Raman, transmission Raman, spatially-offset Raman, and hyper Raman. Raman scattering is not limited to molecular vibration, and it can be applied to rotational, rovibronic, and electronic spectroscopy.

Web Search Results

• Raman spectroscopy - Wikipedia

  Raman spectroscopy is used in chemistry to identify molecules, quantify their concentration, and understand their physical structure. Vibrational frequencies are specific to a molecule's chemical bonds and symmetry. Infrared and Raman spectra both capture data from the "fingerprint" region of organic molecules (wavenumber range 500–1,500 cm−1). The Raman response is not limited to organic molecules. The intensity of spontaneous Raman scattering is linearly proportional to the concentration of a chemical analyte, enabling quantitative chemical analysis, but linear Raman spectroscopy has a relatively weak response and other methods have been employed to improve the sensitivity. The Raman shift frequencies and the shapes of Raman spectral features relate to the atomic and electronic [...] Raman spectroscopy relies upon inelastic scattering of photons, known as Raman scattering. A source of monochromatic light, usually from a laser in the visible, near infrared, or near ultraviolet range is used, although X-rays can also be used. The laser light interacts with molecular vibrations, phonons or other excitations in the system, resulting in the energy of the laser photons being shifted up or down. The shift in energy gives information about the vibrational modes in the system. Time-resolved spectroscopy and infrared spectroscopy typically yield similar yet complementary information. [...] Raman spectroscopy has a wide variety of applications in biology and medicine. It has helped confirm the existence of low-frequency phonons in proteins and DNA, promoting studies of low-frequency collective motion in proteins and DNA and their biological functions. Raman spectroscopy has also been used for label-free characterization of plasma-derived extracellular vesicle and lipoprotein subpopulations, including comparison of their molecular and lipid profiles. Raman reporter molecules with olefin or alkyne moieties are being developed for tissue imaging with SERS-labeled antibodies. Raman spectroscopy has also been used as a noninvasive technique for real-time, in situ biochemical characterization of wounds. Multivariate analysis of Raman spectra has enabled development of a

• Raman Spectroscopy

  Raman spectroscopy is a molecular spectroscopic technique that utilizes the interaction of light with matter to gain insight into a material's make up or

• What is Raman Spectroscopy?

  # What is Raman Spectroscopy? ## Channel: METTLER TOLEDO AutoChem 6.32K subscribers 2.5K likes ### Description 162,942 views Posted: 2022-08-26 Raman spectroscopy is a molecular spectroscopic technique, used in industry and academic laboratories that utilizes the interaction of light with matter to gain insight into a material's makeup or characteristics. Both Raman and FTIR spectroscopy provides a spectrum characteristic of the specific vibrations of a molecule and is valuable for identifying many substances. However, Raman spectroscopy can give additional information about lower frequency modes, and vibrations that give insight into crystal lattice and molecular backbone structure. Learn more about the principles of Raman spectroscopy here: [...] ### Transcript [0:01] [Music] [0:05] raman spectroscopy is an analytical technology used in industry and academic laboratories to understand the structure [0:12] of molecules and the composition of molecular mixtures in a liquid slurry paste or solid phase [0:21] raman is often compared with ir spectroscopy because both provide information about the structure and properties of molecules from their [0:28] vibrational transitions a key difference between brahmin and infrared spectroscopy is that raman is a scattering phenomenon whereas infrared [0:37] is an absorption technique there are two types of scattering rayleigh and ramen [0:45] rayleigh is elastic scattered energy which means the frequency of the scattered photon is the same as the excitation photon frequency

• The Latest Applications in Raman Spectroscopy | Spectroscopy Online

  Advertisement Raman spectroscopy is a versatile forensic analysis method. It enables both qualitative and quantitative analysis by measuring the frequency and intensity of scattered radiations, respectively (1). Raman spectra serve as unique fingerprints for a wide array of compounds, allowing simultaneous tracking of polymers in cell walls and analysis of their molecular composition and structure (2). Its sensitivity to subtle structural changes makes it valuable for comparative tests. Ongoing advancements in Raman techniques and instrumentation further enhance its significance in tissue discovery and characterization (2). [...] Raman spectroscopy remains a popular spectroscopic technique for analytical scientists. It can provide detailed information on the vibrational and rotational modes of molecules, offering insights into chemical bonding, crystal structure, and molecular dynamics. By measuring the energy shifts in scattered light, Raman spectroscopy can identify specific chemical bonds and functional groups within a sample, making it invaluable for materials characterization, pharmaceutical analysis, and forensic science (2). Its non-destructive nature and ability to analyze samples in various states, including solids, liquids, and gases, make Raman spectroscopy an indispensable tool for scientific research and industrial applications (2).

• What is Raman Spectroscopy – Uses and applications

  Skip to content Ibsen Logo Contact us What is raman spectroscopy: Uses and ApplicationsIbsen IT2025-08-14T13:44:24+02:00 # What is Raman Spectroscopy: Uses and applications Raman Spectroscopy is a molecular spectroscopic technique that relies on inelastic scattering of monochromatic light in molecular structures. The incident laser light changes the excitation states of the molecules, and during this process, the molecules will emit light at higher and/or lower wavelengths relative to the excitation wavelength (called Stokes or Anti-Stokes shifts). Each material has its own specific Raman spectrum. Raman scattering can, therefore, be used to identify and quantify the presence and composition of various substances. Image of Spectrometer for Raman Spectroscopy [...] ## Information obtained by Raman Spectroscopy Raman spectroscopy is a powerful analytical technique used to gain detailed information about the molecular structure, chemical composition, and physical properties of materials. Below is an outline of the types of information that can be obtained using this technique: ### Melocular structure and chemical identification Raman spectroscopy provides unique molecular fingerprints, allowing for the identification of chemical compounds and molecular structures. This is possible because each molecule scatters light in a specific way, leading to distinctive spectral patterns. [...] ## Applications of Raman Spectroscopy Raman spectroscopy is a versatile tool used in a wide range of industries and research areas. Its ability to provide molecular-level insights, identify chemical compounds, and monitor changes in materials makes it valuable for solving complex problems. Below are some key Raman spectroscopy applications across different fields: