High-refractive-index optical adhesives (HRIAO) have become an indispensable key material in cutting-edge optical applications such as augmented reality (AR)/virtual reality (VR) glasses, high-performance camera lenses, advanced sensors, and optical communication devices. They go beyond simply bonding components; they are core elements that directly impact optical transmission efficiency, image clarity, system miniaturization, and overall performance.
Why is a high refractive index so important?
At the bonding interface of optical components, if the refractive index of the adhesive does not match that of the adjacent material (such as glass, plastic lenses, or waveguides), significant Fresnel reflection losses can occur. This loss can reduce light transmittance, generate stray light, affect image contrast, and even cause system failure. The value of high-refractive-index optical adhesives lies in their ability to closely match or exceed the refractive index of most optical plastics (such as PC and PMMA) and some optical glasses (typically in the range of 1.50-1.65). This results in:
Significantly reduced interfacial reflection losses: This improves light transmittance and ensures higher light transmission efficiency.
Improves image quality: Reduces glare and ghosting, resulting in clearer, higher-contrast images.
Facilitates miniaturization of optical systems: This allows for the design of more complex and compact optical paths, a key requirement for miniaturized devices such as AR glasses.
Improves overall system efficiency: For optical communication devices and sensors, this translates to higher signal strength and sensitivity.
U-9310: A Cationic Curing High-Refractive Index Solution
Among numerous technology options, cationic curing systems, due to their unique advantages, have become the preferred choice for high-end high-refractive index optical adhesives. Our core product, U-9310, is a high-performance resin developed based on this advanced technology.
Key Advantages of U-9310 Cationic Cure Resin:
Excellent High Refractive Index: U-9310 achieves a refractive index of 1.60 or higher after curing (depending on the formulation), effectively matching a variety of high-refractive optical plastics and glasses, significantly reducing interfacial reflections.
Excellent Optical Performance: Cured resin exhibits extremely high light transmittance (>99%) and extremely low haze, ensuring high-fidelity transmission of optical signals.
Ultra-Low Shrinkage and Stress: The cationic curing mechanism results in extremely low volume shrinkage and minimal internal stress during the curing process, which is crucial for bonding precision optical components and preventing deformation and cracking.
Excellent Weatherability and Stability: The cured bondline exhibits excellent resistance to yellowing, humidity and heat aging, and long-term stability, ensuring the long-term performance of optical systems in harsh environments.
Deep Cure Capability and No Oxygen Inhibition: Cationic curing is unaffected by oxygen inhibition, achieving deep, uniform cure, making it particularly suitable for bonding thick or irregularly shaped optical components.
Excellent process adaptability: UV/visible light-triggered curing is fast, efficient, and easy to integrate into automated production lines. Thermal post-curing is also possible for optimal performance.
Typical Applications of U-9310 High Refractive Index Optical Adhesive:
AR/VR/MR Devices: Bonding waveguides, combiners, and lens assemblies is a core adhesive for achieving lightweight, high-transmittance, and high-definition displays.
Precision Optical Lens Assembly: Bonding aspheric lenses and multi-layer composite lens assemblies reduces reflection loss and improves image quality.
Optical Communication Device Packaging: Bonding optical components within fiber optic connectors, couplers, and isolators ensures low insertion loss and high reliability.
Sensor Packaging: Used for bonding and protecting optical windows in CCD/CMOS image sensors, biosensors, and other applications.
Display Lamination: Providing solutions for specialized display applications requiring high refractive index matching.
Why choose cationic-curing U-9310?
Compared to traditional free radical-curing or epoxy-thermal-curing systems, U-9310 cationic-curing high-refractive index optical adhesive offers a better balance of properties:
Lower stress: Protects delicate optical components from stress-induced birefringence and cracking.
Improved long-term stability: Prevents yellowing and performance degradation, ensuring product life.
Excellent deep-section cure: Ensures complete cure and reliable bonding of thick adhesive layers or complex structures.
Wider environmental adaptability: Less sensitive to temperature and humidity fluctuations, resulting in a more stable curing process.
In the pursuit of higher-performance, smaller, and more reliable optical systems, high-refractive-index optical adhesives play a key role. U-9310 cationic-curing resin, with its high refractive index (RI) of 1.60+, ultra-low shrinkage stress, exceptional optical clarity, and long-term stability, provides designers and engineers with an ideal solution for solving complex optical bonding challenges. More than just an adhesive, it's a core enabling material that unlocks the full potential of next-generation optical devices.