| Raman Spectral Range | Approximately 100–3,200 cm−1 for common fingerprint and functional-group analysis | Covers many molecular-vibration regions used for chemicals, materials, pharmaceuticals, and geological samples. | Confirm the usable range with the selected laser, spectrograph, grating, and detector. |
| Spectral Resolution | Typically about 1–5 cm−1, depending on optical configuration | Higher resolution helps distinguish closely spaced Raman bands and identify subtle material differences. | Request measured resolution data using a recognized calibration standard rather than a nominal value only. |
| Laser Excitation Options | Common wavelengths include 405, 488, 532, 633, and 785 nm | Different wavelengths affect fluorescence, Raman intensity, spatial resolution, and sample photostability. | Check wavelength accuracy, laser stability, available filters, and compatibility with the intended samples. |
| Laser Power Control | Continuously adjustable or software-controlled attenuation from low power to the system maximum | Low-power control reduces fluorescence, heating, bleaching, and laser-induced sample damage. | Verify power at the sample plane, not only at the laser output. |
| Confocal Optical Sectioning | Adjustable confocal pinhole or equivalent spatial-filtering mechanism | Improves rejection of out-of-focus light and enables depth-resolved measurements. | Ask for axial resolution data and confirm whether the pinhole is manually or electronically controlled. |
| Lateral Spatial Resolution | Generally sub-micrometer to approximately 1 µm with visible excitation and a high-numerical-aperture objective | Determines the smallest lateral features that can be chemically distinguished. | Evaluate resolution using the actual objective, wavelength, sample type, and measurement conditions. |
| Axial Resolution | Typically a few micrometers, depending on numerical aperture, wavelength, and confocal settings | Supports three-dimensional chemical profiling and depth-section analysis. | Check whether the stated value is measured in air, through a transparent medium, or under a special setup. |
| Detector Technology | Cooled silicon CCD for visible Raman; extended-range or InGaAs detectors for longer wavelengths | Detector choice influences sensitivity, noise, wavelength coverage, and suitability for near-infrared excitation. | Review quantum efficiency, cooling temperature, dark noise, readout noise, and saturation behavior. |
| Spectrograph Configuration | High-throughput spectrograph with interchangeable or optimized gratings | The optical design balances spectral range, resolution, signal throughput, and acquisition speed. | Confirm grating groove density, entrance aperture, wavelength calibration, and stray-light performance. |
| Raman Mapping | Motorized XY scanning with optional Z movement and programmable step sizes | Enables chemical imaging, particle classification, layer inspection, and defect localization. | Check stage travel, repeatability, minimum step size, autofocus, and total mapping area. |
| Microscope Objectives | Multiple magnifications, commonly including 10×, 20×, 50×, and 100× objectives | Objective selection affects spatial resolution, working distance, collection efficiency, and sample accessibility. | Verify numerical aperture, working distance, correction type, and laser-damage compatibility. |
| Sample Compatibility | Solids, powders, liquids, thin films, polymers, biological specimens, and microstructured materials | A flexible sample interface increases the range of research and quality-control applications. | Confirm holders, immersion options, sealed-liquid cells, temperature accessories, and microscope clearance. |
| Calibration and Measurement Accuracy | Routine calibration using standards such as silicon with a characteristic Raman band near 520.7 cm−1 | Reliable calibration supports accurate peak positions, reproducible results, and instrument-to-instrument comparison. | Request calibration procedures, frequency, traceability, and software correction records. |
| Software and Data Analysis | Spectral acquisition, baseline correction, cosmic-ray removal, peak fitting, mapping, library search, and multivariate analysis | Efficient software improves repeatability and converts spectra into actionable chemical information. | Check raw-data access, audit trails, export formats, user permissions, and compatibility with common analysis tools. |
| Acquisition Speed | Adjustable integration times from milliseconds to several seconds or longer | Flexible acquisition helps balance throughput, signal-to-noise ratio, fluorescence, and sample stability. | Compare signal-to-noise performance at the same laser power, integration time, and sample concentration. |
| Safety and Interlocks | Enclosed beam paths, key-controlled access, laser interlocks, warning indicators, and documented laser classification | Protects users from hazardous optical exposure and supports laboratory safety compliance. | Review safety documentation, applicable laser standards, interlock testing, and operator training requirements. |
| System Stability | Rigid optical construction, temperature management, vibration control, and stable laser alignment | Mechanical and thermal stability are important for long mappings, weak-signal detection, and repeatable measurements. | Request long-duration baseline, wavelength-drift, and repeatability test results under normal laboratory conditions. |
| Service and Documentation | Installation qualification, operating manuals, preventive-maintenance guidance, training, and technical support | Clear documentation and responsive support reduce downtime and improve measurement consistency. | Evaluate service response times, spare-parts availability, warranty terms, training scope, and validation support. |