Key Differences Between Coated and Uncoated Optical Glass
- The function and principle of coating
The performance of optical devices is often influenced by factors such as light reflection, refraction, transmission and scattering. The application of a thin film to the surface of optical glass can effectively enhance these properties. The primary functions of optical glass coating include:
- Increase light transmittance
The surface of optical glass undergoes partial reflection. Coating it with a transparent film is an effective method of significantly reducing reflection, thereby enhancing the transmittance of optical devices.
- Improve wear resistance
The surface of optical glass is prone to scratches or chemical corrosion. Coating it with a film can protect the glass surface and enhance its wear resistance.
- Adjust optical properties
Films of different materials can diffract and interfere with light waves, thereby regulating the transmission, reflection, scattering and other properties of optical devices.
The principle of coating involves the application of a thin film with specific properties to the surface of optical glass by physical or chemical methods. The selection of film materials and thickness is based on the usage requirements.
- The difference between coated and uncoatedglass
The most significant difference between coated and uncoated optical glass surfaces in the manufacturing of optical devices lies in the performance disparity. More specifically, it is expressed as follows:
- Reflectivity
The reflectivity of uncoated optical glass is often between 5% and 10%, while that of coated glass can be reduced to below 0.5%, significantly enhancing the transmittance.
- Dispersion
Uncoated glass exhibits varying refractive indices depending on the wavelength of light, leading to dispersion effects. The glass after coating is effective in reducing dispersion and improving colour reproduction.
- Durability
The surface of coated glass boasts better wear resistance and corrosion resistance, along with a longer service life.
In addition, coated optical glass also possesses more diverse optical properties, allowing for the adjustment of its transmission, reflection, interference and other performances within different wavelength ranges, thereby meeting the requirements of various optical devices.
In general, the coating of optical glass can significantly improve its optical properties, improve the imaging effect and service life of optical devices.
