A Short Guide for Optical Films: Definition, Types, and Applications

Optical films, when first developed, didn’t garner the attention they deserved. But, over the years, their increased usage in semiconductor manufacturing and other such highly critical industries have made them extremely important. Different types of optical films have been manufactured in the recent times and each one of these types perform some very unique functions. Their inherent physical properties are the main reason behind their wide and unique functionality.

Princy A. J | April 25, 2022

Different natural phenomena have frequently attracted curious human minds. Be it thunderstrikes, earthquakes, seed dispersal, or optical illusions, natural events have always been extensively studied, during the course of which new inventions have been materialized. For example, consider a rainbow; study of rainbow and a quest to answer the questions related to it has given birth to a dedicated field of physics called optics. Optics is a branch of science that engages in the study of light and its properties. Right from Plato to Einstein, many physicists have contributed to the field of optics, thereby leading to numerous discoveries and inventions. Optical coatings, optical films, optical fibers, and similar other products work on the scientific principles of optics. These subtle inventions and innovations have changed the world in an irreversible manner.

Optical films are thin coatings that are developed to improve the polarization, reflective/refraction, and transmission properties of a substance. Optical films can be used to layer different substances, ranging from a simple glass to complicated electronic circuits. Additionally, these films also act as anti-corrosion and anti-degradation films, thereby protecting the layered substance from externalities.

Different Types of Optical Films

Depending upon the thickness, refractive index, and other such physical properties, different types of optical films are available in the global optical films market. Some of these types are given here:

Diffuser Optical Film

Diffuser optical films are used to diffuse, i.e., scatter the incident parallel rays of light in different directions so that a glare-free light is produced. Because of this unique functionality, diffuser optical films have varied applicability. The most common use of such films is in the backlight unit of LCD displays, wherein these diffuser films are placed in between the light emitter and the display. Diffuser optical films are also used in cameras, streetlamps, warning display signs, car headlights, etc.

Reflective Polarizer Film

Reflective polarizer films transmit the intended optical polarization while, at the same time, reflecting the rest of the light rays. Not just for visible light spectrum, reflective polarizer films can be manufactured for other types of electromagnetic waves like X-rays, microwaves, etc. In case of these electromagnetic waves too, reflective polarizer films regulate and streamline a mixed array of electromagnetic signals, thereby providing a well-structured polarization. These films are heavily used in manufacturing of optical instruments. Photography industry is also one of the major users of reflective polarizers.

Transmissive Film

Transmissive films are a relatively recent phenomenon; they are used to enhance the sharpness and brightness of LCD displays which are used in various devices. With a thickness of just 60-65 micrometers, these optical films also help in improving the direction control of the image that is being displayed on the LCD screen. Transmissive films have helped in countering the basic problem of brightness loss which is associated with LCD displays. Since only 10% of the light emitted by the emitter reaches the LCD display, transmissive films have become a must so as to increase the efficiency of LCD displays.

ITO Film

ITO, or indium tin oxide, films are manufactured by depositing indium, a rare metal, on films using functional thin film formation technologies or similar scientific methods. These films are typically used in manufacturing of OLED (Organic Light Emitting Diode) displays, anti-static coatings, plasma displays, solar cells, etc. Physical properties of ITO films such as transparency to visible light, low electrical resistivity, and high optical transmittance make them perfect for touch-screen application in the smartphones industry.

The Bottom Line

Optical films have acted as catalysts in bringing about the electronics and the Information Technology revolution. Without them, industries like semiconductor manufacturing, automobile manufacturing, solar cells manufacturing, etc. wouldn’t have reached the level that they have reached today. Research and development in bettering the quality and effectivity of the existing optical films technology as well as coming up with newer technologies will not only help the optical films industry but will surely have a positive spillover effect on other sectors too.

About the Author(s)

Princy A. J

Princy holds a bachelor’s degree in Civil Engineering from the prestigious Tamil Nadu Dr. M.G.R. University at Chennai, India. After a successful academic record, she pursued her passion for writing. A thorough professional and enthusiastic writer, she enjoys writing on various categories and advancements in the global industries. She plays an instrumental role in writing about current updates, news, blogs, and trends.