# Raman Spectroscopy > Measures inelastic photon scattering for chemical identification. Source: https://covalent.com/techniques/optical-analysis/raman-spectroscopy/ Updated: 2026-04-22T23:58:58+00:00 --- ![](https://spcdn.shortpixel.ai/spio/ret_img,q_cdnize,to_auto,s_webp:avif/covalent.com/wp-content/themes/covalent/assets/images/blog-default-banner.jpg) ![](https://spcdn.shortpixel.ai/spio/ret_img,q_cdnize,to_auto,s_webp:avif/covalent.com/wp-content/themes/covalent/assets/images/blog-mobile-banner.jpg) [Core Lab](https://covalent.com/covalent-core-lab/) # Raman Spectroscopy Raman spectroscopy measures inelastic photon scattering, yielding molecular vibrational energy shifts, a distinctive chemical fingerprint. [Add to Quote](#) ## What Is Raman Spectroscopy? Raman spectroscopy analyzes the inelastic scattering of monochromatic light, usually from a laser, to identify molecular vibrations and gain insight into a substance’s structure and composition. Raman scattering occurs when incident photons interact with molecular vibrations or phonons within the sample, causing a shift in energy that results in scattered light with different wavelengths, either higher (anti-Stokes) or lower (Stokes) than the incident light. High Spatial and Depth Resolution ### High Spatial and Depth Resolution Achieves sub-micron mapping with <0.5 µm spatial and <2 µm depth resolution. Versatile Sample Compatibility ### Versatile Sample Compatibility Analyzes solids, liquids, and gases, even through transparent containers, without damaging samples. Enhanced Sensitivity Options ### Enhanced Sensitivity Options Uses SERS and multiple excitation lasers to detect trace compounds across diverse materials. ## Why Use Raman Spectroscopy? To map or identify the structure & chemistry of samples at the sub-micron scale. The Raman signal is often used to identify the type and nature of chemical compounds by comparing the sample signature against reference standards. ### Unique Chemical Fingerprinting Provides distinct molecular signatures for accurate material identification. ### Non-Destructive High-Precision Analysis Delivers structural and chemical insights without altering or damaging samples. ### Wide Industry Applications Supports analysis in semiconductors, pharmaceuticals, [polymers](/applications/polymer-and-plastic-analysis-testing-services/), and advanced materials research. ## Covalent’s Capabilities Offer Raman Spectroscopy for Non‑Destructive Sub Micron Chemical Analysis [Get a Quote](https://covalent.com/get-a-quote/) ## Working Principle A confocal Raman microscope uses a laser to illuminate a microscopic sample and collects the inelastically scattered light through a pinhole to obtain high-resolution chemical information from specific depths within the sample. ### Equipment Used for Raman Spectroscopy: We have many complementary instruments to probe structural and composition of samples to augment information from Raman spectroscopy. #### ThermoFisher Scientific DXR3xi Raman Spectrometer - Multiple Excitation Lasers: - 455 nm. - 532 nm. - 785 nm. - Laser Power with precision controls: 0.1 mW power increments. - Spatial Resolution: Better than 0.5 micron. - Confocal Depth Resolution: Better than 2 micron. - Maximum image area: 101.6 mm x 76.2 mm. [View Spec Sheet](https://www.thermofisher.com/order/catalog/product/in/en/IQLAADGABFFAHCMAPA) ### Key Differentiators - Excitation in the VIS and NIR for various sample types. - Micron and sub-micro scale information can be obtained. - Surface enhanced Raman scattering (SERS) can provide enhanced sensitivity for certain compounds. #### Strengths - Non-destructive. - Can measure samples through glass and other transparent containers. - Works for most samples, liquids, gases or solids. - Confocal microscopy provides depth resolution (~1-2um) for non-destructive depth profiling of layered. #### Limitations - Laser confocal microscope configuration probes a small spot/volume, around 1um, which requires multiple spots to adequately sample heterogeneous materials. Fast mapping of many particles or locations can be beneficial. - Most metals are difficult/impossible to measure. - Highly fluorescent samples can overwhelm the weaker Raman signal, in certain cases higher or lower excitation wavelengths can overcome this. - Certain vibrational modes are forbidden due to sample symmetry. Two colleagues working together on a laptop, discussing a project in a bright, professional environment. ## Unsure Whether Raman Spectroscopy Is Right for You? Learn more about using Raman spectroscopy chemical analysis services today. [Talk to an Expert](https://covalent.com/contact-us/) ## Sample Information Example Outputs Sample Requirements [https://covalent.com/wp-content/uploads/2025/12/raman-spectroscopy-output1.jpg](https://covalent.com/wp-content/uploads/2025/12/raman-spectroscopy-output1.jpg) Comparison of Raman spectra for polystyrene, polypropylene, and high-density polyethylene, illustrating distinct peak patterns that enable clear discrimination and identification of these polymers. [https://covalent.com/wp-content/uploads/2025/12/raman-spectroscopy-output2.jpg](https://covalent.com/wp-content/uploads/2025/12/raman-spectroscopy-output2.jpg) Raman spectra of boron nitride, silicon carbide, and diamond highlighting the distinct strong phonon peaks characteristic of each material. ### What we accept: Sample must be stable under laser irradiation; reduced power can be used to mitigate. Strongly absorbing samples can be sensitive. ## Use Cases - Analysis of Graphite Quality - Strain Mapping in Semiconductors - Mapping Active Ingredients in Pharmaceuticals - Polymer Identification - ![Raman Spectroscopy in Graphite Quality Analysis](https://spcdn.shortpixel.ai/spio/ret_img,q_cdnize,to_auto,s_webp:avif/covalent.com/wp-content/uploads/2025/11/uc-analysis-of-graphite-quality.jpg) ### Analysis of Graphite Quality Raman spectroscopy evaluates graphite crystallinity and defect density by examining the intensity and shape of the D, G, and 2D bands. In addition to quality different polymorphs (nanotubes, graphene, C60, diamond, etc.) can be easily distinguished. - ![Strain Mapping in Semiconductors](https://spcdn.shortpixel.ai/spio/ret_img,q_cdnize,to_auto,s_webp:avif/covalent.com/wp-content/uploads/2025/11/Semiconductor-Battery-and-Materials-Industries.jpg) ### Strain Mapping in Semiconductors Raman shifts of phonon modes are sensitive to strain and provide a non-destructive way to detect and quantify strain/stress in semiconductor wafers and devices. Using the mapping capabilities strain gradients at the microscale can be characterized. - ![Mapping Active Ingredients in Pharmaceuticals](https://spcdn.shortpixel.ai/spio/ret_img,q_cdnize,to_auto,s_webp:avif/covalent.com/wp-content/uploads/2025/11/Pharmaceutical-and-Medicine.jpg) ### Mapping Active Ingredients in Pharmaceuticals Raman imaging allows spatially resolved identification and distribution of active pharmaceutical ingredients (APIs) and excipients within tablets and other solid formulations. Often used to [QA/QC](/solutions/quality-control-qc-testing/) in pharmaceutical manufacturing. Different crystal polymorphs can also be distinguished. - ![Polymer Identification](https://spcdn.shortpixel.ai/spio/ret_img,q_cdnize,to_auto,s_webp:avif/covalent.com/wp-content/uploads/2025/11/Polymers.jpg) ### [Polymer Identification](/applications/polymer-and-plastic-analysis-testing-services/) Raman spectroscopy enables identification of polymer materials by comparison to an extensive reference library. This is well suited for small particles, thin layers and localized contamination where FTIR is not practical. Raman can also measure particles behind transparent materials like glass as it relies on visible or NIR light. ## Complementary Techniques - [FTIR](https://covalent.com/techniques/chemical-analysis/fourier-transformed-infrared-spectroscopy-ftir/) and AFM-IR provide complementary analysis of bonding vibrational modes, particularly for organic samples. - [SEM-EDS](https://covalent.com/techniques/electron-microscopy/scanning-electron-microscopy-sem/) provides complementary chemical information. - [XRD](https://covalent.com/techniques/morphology-structural-analysis/x-ray-diffraction-xrd/) provides complementary structural information. [Atomic Force Microscopy (AFM) Analysis](https://covalent.com/techniques/morphology-structural-analysis/atomic-force-microscopy-afm-analysis/) Maps nanoscale topography and material properties with a sharp probe. [Explore](https://covalent.com/techniques/morphology-structural-analysis/atomic-force-microscopy-afm-analysis/) [Add to Quote](#) [Fourier Transform Infrared Spectroscopy (FTIR)](https://covalent.com/techniques/chemical-analysis/fourier-transformed-infrared-spectroscopy-ftir/) Rapid, non-destructive molecular fingerprinting across materials. [Explore](https://covalent.com/techniques/chemical-analysis/fourier-transformed-infrared-spectroscopy-ftir/) [Add to Quote](#) [X-ray Diffraction (XRD)](https://covalent.com/techniques/morphology-structural-analysis/x-ray-diffraction-xrd/) Non-destructive analysis of crystal phases, lattice, and strain. [Explore](https://covalent.com/techniques/morphology-structural-analysis/x-ray-diffraction-xrd/) [Add to Quote](#) ## Why Choose Covalent for Your Raman Spectroscopy Needs? Covalent offers comprehensive Raman spectroscopy services for materials characterization, enabling analysis of vibrational modes, chemical composition, and structural properties of various samples. ## Frequently Asked Questions Identifying the right test can be complex, but it doesn’t have to be complicated. Here are some questions we are frequently asked. - ### What is spatial resolution? The spatial resolution laterally can be better than 1um using a high numerical aperture objective. Individual point spectra and maps are possible. - ### What is depth resolution? Depth resolution is 1-2um using dry objectives and can be improved using oil immersion objectives. A variety of well characterized immersion oils are available to minimize overlap of the oil Raman peaks with the sample. - ### What types of materials can be analyzed? Solids, liquids, and gases—including pharmaceuticals, polymers, minerals, biological samples, and more. Non-volatile liquids can be measured easily as drops on metal oil and volatile or hazardous liquids can be measured in a cuvette. Resources ![](https://spcdn.shortpixel.ai/spio/ret_img,q_cdnize,to_auto,s_webp:avif/covalent.com/wp-content/themes/covalent/assets/images/resource-bg-c.svg) Resources ![](https://spcdn.shortpixel.ai/spio/ret_img,q_cdnize,to_auto,s_webp:avif/covalent.com/wp-content/themes/covalent/assets/images/resource-bg-o.svg) [![cyberTECHNOLOGIES CT300: The Swiss Army Knife (SAK) of Optical Metrology](https://spcdn.shortpixel.ai/spio/ret_img,q_cdnize,to_auto,s_webp:avif/covalent.com/wp-content/uploads/2025/09/covalent-academy-episode-36-banner-FINAL2_Academy-Zoom-768x768.png) Webinar cyberTECHNOLOGIES CT300: The Swiss Army Knife (SAK) of Optical Metrology 59 mins Mar 26, 2024](https://covalent.com/webinars/cybertechnologies-ct300-the-swiss-army-knife-sak-of-optical-metrology/) [![Fast Characterization of Nanometer Thin to Thick Coatings Using Pulsed-RF Glow Discharge Optical Emission Spectrometry](https://spcdn.shortpixel.ai/spio/ret_img,q_cdnize,to_auto,s_webp:avif/covalent.com/wp-content/uploads/2025/09/covalent-academy-episode-28-banner_Zoom-768x768.png) Webinar Fast Characterization of Nanometer Thin to Thick Coatings Using Pulsed-RF Glow Discharge Optical Emission Spectrometry 60 mins Dec 02, 2021](https://covalent.com/webinars/fast-characterization-of-nanometer-thin-to-thick-coatings-using-pulsed-rf-glow-discharge-optical-emission-spectrometry/) [![Shining a Light on Optical Modeling for Spectral Ellipsometry](https://spcdn.shortpixel.ai/spio/ret_img,q_cdnize,to_auto,s_webp:avif/covalent.com/wp-content/uploads/2025/09/Ep15_SAM-with-PVA-TePla-Facebook-225x225-2.png) Webinar Shining a Light on Optical Modeling for Spectral Ellipsometry 60 mins Aug 06, 2020](https://covalent.com/webinars/shining-a-light-on-optical-modeling-for-spectral-ellipsometry/) [![Laser Ablation Inductively Coupled Plasma Mass Spectroscopy: Not Just Rocks](https://spcdn.shortpixel.ai/spio/ret_img,q_cdnize,to_auto,s_webp:avif/covalent.com/wp-content/uploads/2025/09/Ep30-LAICPMS-with-Teledyne_Zoom-768x768.png) Webinar Laser Ablation Inductively Coupled Plasma Mass Spectroscopy: Not Just Rocks 60 mins Feb 10, 2020](https://covalent.com/webinars/laser-ablation-inductively-coupled-plasma-mass-spectroscopy-not-just-rocks/) [![Optical Characterization Testing](https://spcdn.shortpixel.ai/spio/ret_img,q_cdnize,to_auto,s_webp:avif/covalent.com/wp-content/uploads/2025/06/Optical-Characterization.svg) Application Optical Characterization Testing Jun 10, 2025](https://covalent.com/applications/optical-characterization-services/) [![Comparison of Raman Spectroscopy and Fourier Transformed Infrared (FTIR) Spectroscopy for Advanced Technology R&D and Quality Control](https://spcdn.shortpixel.ai/spio/ret_img,q_cdnize,to_auto,s_webp:avif/covalent.com/wp-content/uploads/2023/10/Comparison-of-Raman-Spectroscopy-and-Fourier-Transformed-Infrared-FTIR-.jpg) Whitepaper Comparison of Raman Spectroscopy and Fourier Transformed Infrared (FTIR) Spectroscopy for Advanced Technology R&D and Quality Control Oct 20, 2023](https://covalent.com/resource-library/comparison-of-raman-spectroscopy-and-fourier-transformed-infrared-ftir-spectroscopy-for-advanced-technology-rd-and-quality-control/) Need Expert Guidance? Our experts can help you determine if this approach is the best fit for your samples and discuss the next steps. [Talk to a Materials Scientist](https://covalent.com/contact-us/)