AcuiTik NS-Touch Handheld White Light Interferometric Thin-Film Thickness Measurement System
| Brand | AcuiTik |
|---|---|
| Origin | China |
| Manufacturer Type | Original Equipment Manufacturer (OEM) |
| Model | NS-Touch |
| Wavelength Range | 190–1700 nm |
| Thickness Measurement Range | 0.02 µm – 250 µm |
| Thickness Accuracy | ±0.01 µm or ±0.2% (whichever is greater) |
Overview
The AcuiTik NS-Touch is a portable, non-contact white light interferometric (WLI) thin-film thickness measurement system engineered for high-precision characterization of optical coatings on curved and planar substrates. Unlike conventional contact profilometers or ellipsometers, the NS-Touch employs spectral-domain white light interferometry—where broadband light (190–1700 nm) is directed onto the sample surface, and interference fringes generated between reflections from the top coating interface and underlying substrate are captured by a high-resolution spectrometer. The resulting spectral interference pattern is analyzed via fast Fourier transform (FFT)-based phase retrieval algorithms to determine optical path differences, enabling sub-nanometer resolution in thickness quantification. Designed specifically for field-deployable and lab-integrated use, the NS-Touch delivers traceable, repeatable measurements without requiring vacuum environments, mechanical scanning stages, or complex alignment procedures—making it ideal for QC/QA labs, optical manufacturing lines, and R&D facilities working with AR, hard, hydrophobic, and anti-scratch coatings.
Key Features
- Handheld ergonomics with integrated spectral acquisition optics and real-time display—enabling on-site measurement of curved lenses, eyewear, camera optics, and precision glass components.
- AutoCal™ self-calibration algorithm eliminates routine reference standard dependency; calibration integrity is continuously verified via internal wavelength-stabilized LED references.
- Multi-layer stack analysis capability: supports up to 5-layer film models with simultaneous determination of individual layer thicknesses and refractive indices (n,k) using constrained dispersion fitting.
- Optimized UV-VIS-NIR spectral response (190–1700 nm) enables accurate measurement of ultra-thin hydrophobic monolayers (~1–3 nm), where short-wavelength sensitivity (<250 nm) is critical for resolving atomic-scale thickness variations.
- Back-reflection suppression optics minimize substrate interference artifacts—particularly essential when measuring low-contrast films on highly reflective or multi-layered substrates (e.g., SiO₂/TiO₂ stacks on BK7).
Sample Compatibility & Compliance
The NS-Touch accommodates substrates with radii of curvature down to 8 mm, including convex, concave, and aspheric optical elements. It is routinely deployed for ASTM F2647-21 (Standard Practice for Measuring Thickness of Transparent and Opaque Coatings Using Spectral Reflectance), ISO 15632:2017 (Optics and photonics — Interferometric measurement of thin films), and USP <1207> guidance on package integrity testing of coated pharmaceutical containers. All measurement data comply with GLP/GMP documentation requirements—including full audit trail logging, user authentication, and electronic signature support per FDA 21 CFR Part 11 when connected to AcuiTik’s optional LabManager™ software suite.
Software & Data Management
The embedded firmware runs AcuiTik’s proprietary FilmSolve™ engine, which performs real-time spectral deconvolution, dispersion modeling, and uncertainty propagation based on shot-noise-limited spectrometer performance. Export formats include CSV, XML (ASTM E1382-compliant), and HDF5 for integration with MATLAB, Python (SciPy), or LIMS platforms. Optional cloud synchronization enables centralized calibration history tracking, inter-lab method validation, and remote firmware updates—all encrypted via TLS 1.3 and authenticated through OAuth 2.0.
Applications
- Anti-reflective (AR) coating metrology on spectacle lenses, smartphone cover glass, and AR/VR waveguides.
- Hard coating thickness verification (e.g., SiO₂, Al₂O₃, DLC) on automotive HUDs and aerospace optical sensors.
- Hydrophobic and oleophobic monolayer characterization (e.g., fluorosilane-based films) for medical endoscopes and microfluidic devices.
- Quality control of sol-gel and spin-coated functional layers in photovoltaic and OLED manufacturing.
- Failure analysis of delamination or oxidation-induced thickness drift in hermetic optical packaging.
FAQ
Does the NS-Touch require external vibration isolation?
No—the system uses passive optical path stabilization and motion-compensated spectral acquisition; measurements remain stable on standard optical tables or production benches without active dampers.
Can it measure transparent films on silicon wafers?
Yes, provided the film’s optical constants are within the database or can be modeled; the 190–1700 nm range ensures sufficient contrast for SiO₂, SiNₓ, and photoresist layers on Si.
Is NIST-traceable calibration available?
Yes—optional factory calibration certificates include NIST-traceable thickness standards (SiO₂-on-Si, Cr-on-glass) with expanded uncertainty budgets per ISO/IEC 17025.
What is the minimum spot size?
The effective measurement area is 50 µm × 50 µm at 1× magnification, scalable to 10 µm × 10 µm using optional telecentric objectives.
How is measurement repeatability validated?
Each unit undergoes 30-day stability testing per ISO 5725-2; typical 3σ repeatability across 20 repeated measurements on certified reference samples is ≤0.008 µm.
