Briefly describe the application principle of optical coating

With the development of technology and economic globalization, humanity has entered the knowledge economy and information society today. And accompanied by; Made in China; The development of optical manufacturing is in the ascendant on the land of Chinese Mainland. Chinese optical manufacturing has begun to play an important role on the international economic stage, with China's production of optical glass and optical components nearly ranking first. Optical thin film is one or more layers of film deposited on the surface of optical components to alter their surface characteristics. It can be a metal film, a dielectric film, or a combination of these two types of films. Optical thin film is an indispensable part of various advanced optoelectronic technologies. It not only improves system performance, but also is a necessary means to meet design goals. The application fields of optical thin film cover various aspects of optical systems, including laser systems, optical communication, optical display, optical storage, etc. The main optical thin film devices include reflective films, anti reflective films, polarizing films, interference filters, and spectrometers. They have been widely applied in the national economy and defense construction, and have received increasing attention from scientific and technological workers.

At present, there are more than 60 commonly used varieties of optical coating materials, and their varieties and application functions are constantly being developed. In recent years, metal film systems have been developed. When the thickness of gold, silver, copper, and aluminum is 7-20um, their transmittance for visible light is 50%, while the transmittance for infrared light is less than 10%. This type of film has been successfully applied to the panels of the Apollo spacecraft, allowing for the transmission of some visible light while reflecting almost all infrared light for thermal control. The following article mainly introduces the characteristics, principles, and classification of optical thin films.

Definition of Optical Thin Films

A type of optical medium material composed of thin layered media that propagates light beams through interfaces. The application of optical thin films began in the 1930s and has been widely used in the fields of optics and optoelectronics to manufacture various optical instruments. The preparation requirements for the strip are high and precise.

The definition of optical thin film is: a thin and uniform dielectric film layer that adheres to the surface of an optical device during the propagation path of light. When passing through the layered dielectric film layer, it exhibits characteristics such as reflection, transmission (refraction), and polarization, in order to achieve various special forms of light such as complete transmission of light or complete reflection or polarization separation of light in one or more wavelength ranges that we want.

Optical thin films are ubiquitous in our lives, from precision and optical equipment, display devices to optical thin film applications in daily life; For example, the glasses, digital cameras, various household appliances, or anti-counterfeiting technology on banknotes that we usually wear can all be called extensions of optical film technology applications. Without optical thin film technology as the foundation for development, modern optoelectronic, communication, or laser technologies would not have made progress, which also demonstrates the importance of research and development in optical thin film technology.

Optical thin film refers to the process of depositing or coating one or more layers of dielectric film or metal film, or a combination of these two types of films, on optical components or independent substrates to alter the transmission characteristics of light waves, including transmission, reflection, absorption, scattering, polarization, and phase change. Therefore, through appropriate design, the transmittance and reflectivity of different wavelength components can be adjusted, and light with different polarization planes can also have different characteristics.

Generally speaking, the production methods of optical thin films are mainly divided into dry and wet production processes. The so-called dry type refers to the absence of liquid throughout the entire processing process. For example, vacuum evaporation is a process in which solid raw materials are heated by electrical energy in a vacuum environment, and after being transformed into gas, they adhere to the surface of a solid substrate to complete the coating process. The gold, silver, or metallic packaging films used for decoration in daily life are products manufactured by dry coating method. However, considering actual mass production, the scope of application for dry coating is smaller than that of wet coating. The general method of wet coating is to mix various functional components into liquid coatings, apply them on the substrate in different processing methods, and then dry and cure the liquid coatings to make products.

Ruicheng Optoelectronics can undertake various optical coating products. Welcome to inquire by phone.