As glass evolves from a structural material into an active, functional surface, the coatings on top define its true performance. This article examines how spectroscopy enables researchers and manufacturers to measure, control, and optimise coatings, driving both dependable quality and innovation in energy-efficient, self-cleaning, and smart glass technologies.
Spectroscopy in glass and coatings: precision meets innovation
Glass has always been one of the most reliable and versatile materials in modern technology. From architecture and automotive to electronics and energy, it defines how we live and interact with our environment. But the true performance of glass today comes not from the material itself, but from the coatings applied to its surface.
These thin, functional layers determine how glass interacts with light, heat, and even dirt. Low-emissivity (low-E) coatings improve insulation and energy efficiency in buildings. Anti-reflective films keep screens and optical devices clear. Self-cleaning coatings help windows stay spotless, while new smart coatings can filter UV light, fight bacteria, or even adapt to changing environmental conditions.
All of these coatings share one requirement: precision. Small variations in layer thickness, optical response, or material composition can compromise performance. That’s why spectroscopy has become indispensable, offering fast, non-destructive measurements that provide deep insight into optical behavior and material consistency.
Glass under pressure: the demand for smarter coatings
As glass moves into more advanced roles, expectations keep rising. Building-integrated solar glazing must balance transparency with thermal control. Automotive glass must block UV and infrared light while maintaining clarity and strength. Displays demand glare-free, color-accurate surfaces that withstand years of use.
At the same time, innovation continues to push the boundaries. Researchers are developing self-cleaning coatings based on titanium dioxide (TiO₂) that use sunlight and rain to break down and remove dirt, a process validated through UV-Vis spectroscopy, which measures both optical clarity and photocatalytic efficiency (Scientific Reports, 2017).
Others are creating anti-reflective nanostructures to minimise reflection and boost light transmission across the visible spectrum, a crucial advantage in displays and solar panels. Studies in the Journal of Optics (2025) demonstrated that precise layer control, verified through spectroscopic analysis, leads to significant improvements in efficiency and brightness.
And beyond that, a new class of functional coatings is emerging: adaptive or “smart” layers that change their optical properties in response to light, temperature, or voltage. Each of these innovations introduces new measurement challenges, and spectroscopy provides the clarity needed to understand and refine them.
The hidden challenges behind innovation
Pushing glass into new roles isn’t simple. Coatings must stay uniform over large surfaces, remain stable under temperature swings and UV exposure, and maintain performance over years of operation.
Even minor deviations, a few nanometers in thickness or subtle optical drift, can lead to reduced efficiency or visual defects.
Traditional quality checks often miss these subtleties. Spectroscopy fills that gap by providing real-time, highly sensitive feedback on both optical and structural behaviour. This allows researchers and manufacturers to monitor coating performance during deposition, validate film uniformity, and catch defects early in the process.
How spectroscopy supports glass and coating development
Spectroscopic techniques address many of the industry’s most pressing measurement needs:
- Transmission and reflection spectroscopy (UV-Vis-NIR) quantifies how coatings interact with light across the spectrum. It’s essential for energy-efficient glazing, where manufacturers must balance visible transparency with infrared blocking.
- Thin-film metrology uses interference patterns to determine coating thickness with nanometer precision. For anti-reflective and low-E coatings, this directly links to performance and consistency.
- Raman spectroscopy reveals molecular composition, detects stress in glass substrates, and confirms material phases in advanced coatings.
- Colorimetry and radiometry ensure aesthetic and optical quality, crucial for architectural glass and consumer displays.
- And in-line spectroscopy integrates directly into production environments, enabling automated, continuous monitoring of coating deposition. This approach provides immediate feedback, helping manufacturers minimize waste and maintain uniformity at industrial scale.
From research to production: real-world examples
In one study published in Scientific Reports (2017), researchers used UV-Vis spectroscopy to characterize self-cleaning TiO₂ films. The technique validated transparency and confirmed the films’ ability to degrade organic residues under sunlight, proving both functional performance and optical integrity.
A more recent study in the Journal of Optics (2025) examined nanostructured anti-reflective coatings on glass, using spectroscopy to verify improvements in light transmission and uniformity. These findings illustrate how optical measurement drives material optimization, turning experimental coatings into reliable industrial products.
Avantes in glass and coating innovation
Avantes spectrometers are used across the glass and coatings industry, from R&D labs to large-scale production. Known for modularity and precision, they deliver reliable performance even in challenging environments.
Common applications include:
- Real-time transmission and reflection monitoring
- Thin-film thickness and interference analysis
- Colour and radiometric evaluation
- In-line process control during coating deposition
Instruments such as the AvaSpec-ULS2048x64 and the AvaSpec-HERO combine high sensitivity with fast acquisition speeds, enabling both laboratory flexibility and industrial integration. Researchers and manufacturers use Avantes systems to fine-tune coatings, verify durability, and optimize energy-efficient glazing.
Looking ahead
As industries demand more energy-efficient, durable, and multifunctional glass, coatings will continue to define what glass can do. From smart windows that adapt to sunlight to advanced optical films for displays and sensors, the next generation of glass will depend on accurate, real-time optical data.
Spectroscopy will remain at the centre of that progress, helping innovators design better coatings, verify performance, and bring advanced glass technologies to market more quickly.
Byline: Lotte Sijbers, Marketing & Communications Specialist, Avantes
