Raman Spectroscopy System – WEVE | Core Technology & Lineup

⁂ Pixel Shift from CCD Cooling is a Hidden but Critical Source of Measurement Error

Thermoelectrically cooled CCDs are typically brought below –40°C to enhance the signal-to-noise ratio. However, this cooling process can cause slight mechanical contraction of the CCD chip, potentially affecting wavelength alignment. In the experiment shown above, spectral measurements taken over four hours after cooling to –50°C revealed that, although the CCD’s center remained stable, the left and right regions shifted by more than two pixels. This non-uniform pixel shift, likely due to residual thermal gradients or mechanical stress, can introduce significant wavelength errors, particularly problematic in high-precision or time-resolved Raman spectroscopy.

⁂ Prolonged thermal effects may degrade spectrometer accuracy

Over time, thermal warping, mechanical strain, and internal stress can build up in the CCD and optical components, progressively altering the spectrometer's alignment. Unlike transient pixel shifts, these long-term structural changes cannot be corrected through routine calibration alone. As a result, spectral accuracy declines, calibration becomes less predictable, and reliance on expert maintenance increases—ultimately undermining confidence in analytical results.

To address the issue of spectral drift and maintain precise measurement accuracy, WEVE created its unique DualTrack™ automatic wavelength calibration system. Each time the system is turned on or at the user's request. DualTrack™ fully calibrates all spectrometer parameters using a built-in reference lamp. The process takes about one minute and requires just one click to initiate.

Key features include:

• Automatic adjustment for pixel shifts caused by temperature fluctuations or prolonged use

• Consistently stable wavelength alignment without the need for frequent manual recalibration

• Rapid operation that does not disrupt ongoing measurements or workflow processes

•Average Absolute Error : 0.01595 nm (Based on resolution: 0.07 nm/pixel @ 1200 gr/mm)

•Maximum Error : 0.043 nm

•Coefficient of Determination (R²): 0.99999987 (A value close to 1 indicates very high measurement reliability.)

*Without regular calibration, factors like temperature changes and mechanical distortion can reduce the R² value to around 0.98–0.99, potentially affecting the accuracy and reliability of analysis.

WEVE’s DualTrack™technology

delivers near-perfect calibration accuracy, ensuring outstanding stability and reliability for high-precision spectroscopic measurements.

🚫Laser Wavelength Instability

The wavelength of a laser, especially in DPSS and diode types, can shift slightly due to changes in temperature, fluctuations in power supply, or the passage of time. These variations can directly affect Raman spectroscopy results, leading to peak position errors, inaccurate wavelength calibration, and reduced reproducibility.

🚫Restricted grating choices and inflexible system architecture

Spectral analysis often demands various gratings to cover different wavelength ranges and optimize diffraction efficiency. Yet, most spectrometer systems can only hold three to four gratings at a time, and adding more usually increases mechanical complexity and design constraints. Swapping gratings often requires technical know-how and time-consuming wavelength recalibration. As a result, even when multiple gratings are available, they are seldom utilized efficiently in practical use.

✅You choose the grating; the system handles the precision.

WEVE’s QuickAlign™ Grating System is designed for easy installation of your desired grating into a single slot, giving users the flexibility to select and swap gratings as needed. With no restrictions based on wavelength range or efficiency characteristics, a wide variety of gratings can be used freely. After replacement, the DualTrack™ auto-calibration system precisely realigns the laser wavelength, ensuring consistent analytical accuracy with enhanced user convenience. To take precision a step further, WEVE incorporates a high-precision dual rotary encoder. With a control error of less than 5 arcseconds (0.0014 degrees), it ensures extremely accurate control of the grating’s rotation position delivering excellent repeatability and stability even in environments requiring fine adjustments.

🚫 Conventional Czerny-Turner spectrometers

Conventional Czerny-Turner spectrometers face fundamental design challenges due to their grating-based architecture. They are prone to optical aberrations like astigmatism and coma, which cause shifts in the focal point depending on the position on the CCD. As a result, resolution and signal consistency can vary across the detector, meaning that even under the same measurement conditions, the spectral output may differ based solely on where it lands on the CCD.

✅ WEVE's Aberration-Corrected Optical Design

WEVE has fundamentally overcome structural limitations through its aberration-corrected optical design, delivering consistent focus and sharp spectral images across all CCD positions and the entire wavelength range. By maintaining uniform optical conditions regardless of measurement location or spectral range, it ensures high signal output along with exceptional precision, repeatability, and stability. This technology is integrated into WEVE’s high-speed, high-precision spectroscopic instruments, enabling reliable analytical results in a wide range of research and industrial applications.

Stage Scanning (WEVE Applied).

Measurement Speed: Achieves equivalent speed to laser scanning, based on CCD readout

Aberration Issues: Free from aberration issues, compatible from UV to NIR with a single system

Mapping Range: Scalable to large areas (several cm² or more)

Sample Movement: Sample is moved by precision stage for fine control

Alignment & Reproducibility: High repeatability and stability with precision stage alignment

Recommended Applications: Widely applicable to materials analysis, process monitoring, and industrial/research use

WEVE’s analysis software is integrated with a globally recognized spectral library from Wiley, enabling fast and accurate identification of unknown Raman spectra through a database of tens of thousands of validated entries and high-speed matching algorithms. It supports precise analysis of not only pure substances but also complex mixtures, offering the following advanced features:

•Automated Component Identification in Mixtures
Analyze complex samples using a library of over 26,000 reference spectra, identifying each component step by step.

•Expandable Identification Range
Users can import their own spectral data to expand the identification scope to include novel or unregistered substances.

•Intelligent Sequential Matching Algorithm
The system first matches the most similar compound, then analyzes the remaining spectral data to determine the full composition of the mixture.

•Configurable Number of Components
Set a maximum number of components to be identified, enabling efficient and goal-oriented analysis.

Measured(nm)	Standard Line(nm)	Deviation(nm)
594.44	594.483	0.043
597.51	597.553	0.043
602.97	603	0.03
607.41	607.434	0.024
609.61	609.616	0.006
614.3	614.306	0.006
616.34	616.359	0.019
621.73	621.728	-0.002
626.64	626.65	0.01
630.46	630.479	0.019
633.43	633.443	0.013
638.28	638.299	0.019
640.2	640.225	0.025
650.66	650.653	-0.007

653.29	653.288	-0.002
659.91	659.895	-0.015
667.84	667.828	-0.012
671.72	671.704	-0.016
692.94	692.947	0.007
703.24	703.241	0.001
717.4	717.394	-0.006
724.54	724.517	-0.023

Convallaria plant (microscopic sample) 2D int

Convallaria plant (microscopic sample) 3D

600gr spectrum image 2D